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<title>-Forthcoming Articles</title>
<description>Forthcoming Articles</description>
<link>https://rockmech.whrsm.ac.cn</link>
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<docs>https://rockmech.whrsm.ac.cn/EN/current.shtml</docs>
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<title><![CDATA[Degradation mechanism and equivalent simulation method of shear strength of limestone stylolite under immersion]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43747.shtml]]></link>
<description><![CDATA[Limestone is relatively dense and has low permeability. Its internal structural weak planes act as conduits for water within the rock mass，which can lead to engineering instability and failure. To examine the degradation characteristics and mechanisms of shear mechanical properties of limestone stylolite under immersion，the stylolite was categorized based on field investigations，and specimens were prepared for test. The findings showed that stylolite with a width of b＜1 mm exhibited similar characteristics to limestone. The impact of immersion was primarily evident in the reduction of the cohesion c，though this decline was not substantial (approximately 11.0%). Stylolite with 1 mm&le;b&le;5 mm and b＞5 mm predominantly demonstrated a decline in the internal friction angle( ) after immersion. The reduction rates reached 21.2% and 30.9%，respectively. The stylolite is composed of suture membranes on both sides and metasomatic dolomite in the middle. The stylolite comprising metasomatic dolomite with a width of b＜1 mm is exceedingly rare. The infiltration of water primarily weakens the bonding force between the membrane and the bedrock. Stylolite with a width of 1 mm&le;b&le;5 mm and b＞5 mm are more susceptible to sliding and a reduction in the after immersion. This is due to the dissolution of the dolomite at the edges. The analysis demonstrates that the solubility of metasomatic dolomite is in close proximity to the reduction in ，which can be employed to quantify the impact of immersion on the stylolite. In light of the aforementioned findings，a simulation method for assessing the weakening of interface units due to changes in suture solubility was proposed. The deformation curve and failure process calculated by this method are in good agreement with the test results，and are able to simulate the frictional sliding of particles in the shear process of the sample effectively. This can serve as a reference point and a source of guidance for the simulation of limestone sutures.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YANG Chao1，2，LI Tianyi1，2，WANG Jiao1，2，JIANG Haonan2，XIONG Yun2，3，PAN Huixiong3]]></author>
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<title><![CDATA[Deformation characteristics of rock mass under dislocation of deep-buried strike-slip fault and its influence by geostress]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43746.shtml]]></link>
<description><![CDATA[Fault dislocation causes serious deformation of rock mass，which leads to the destruction of deep-buried structures such as deep-buried tunnels. In order to study the deformation characteristics of rock mass caused by fault dislocation and its influence by geostress under the condition of deep-buried geostress，based on the central Yunnan water diversion project as the engineering background，firstly，the physical model test of deep-buried strike-slip fault dislocation was carried out，and the deformation characteristics of rock mass under the action of fault dislocation were studied. Then，the nonlocal model is applied to the numerical simulation study，and the influence of geostress on the deformation characteristics of rock mass is analyzed. The results obtained are as follows：(1) Under the action of fault dislocation，the main fracture develops within the fracture zone，and the fault undergoes shear movement along this main fracture；(2) Rock mass displacement attenuates from the footwall toward the hanging wall，with the displacement distribution exhibiting partitioning near the main fracture，and The displacement distribution curves exhibit S-shaped pattern. Equivalent strain localization band develops within the fracture zone，with the strain distribution curves exhibiting a single-peak pattern；(3) The soil pressure is released near the main fracture，the soil pressure of the footwall increases，and the soil pressure of the hanging wall remains constant；(4) The nonlocal model can effectively reproduce the test results，and the geostress affects the angle of the equivalent strain localization band and the peak strain. The research achievement expands the understanding of the deformation characteristics of rock mass under the action of fault dislocation，provides a research basis for the analysis of the failure characteristics of the deep-buried tunnel，and has guiding significance for the construction design of the cross-fault deep-buried tunnel.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Ning1，2，ZHOU Hui1，2，GAO Yang1，2，ZHU Yong1，2，LU Jingjing1，2，ZHAO Chengwei1，2，CHENG Guangtan3]]></author>
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<title><![CDATA[Study on static and dynamic shear characteristics of geotextile- residual soil interface considering wet-dry effect]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43745.shtml]]></link>
<description><![CDATA[Geotextiles are widely used for slopes reinforcement in granite residual soil areas，but the static and dynamic shear characteristics of geotextile-granite residual soil interfaces considering wet-dry conditions remain unclear. Monotonic shear tests and cyclic shear tests were conducted on the interface between geotextile and granite residual soil considering wet-dry effects. The development of shear stress-displacement relationships，shear strength parameters and shear stiffness variation with wet-dry cycles and wet-dry amplitudes was analyzed. The results show that in the case of monotonic shear process，the interface roughness gradually increases with wet-dry proceesses. Compared to wet-dry amplitude，the wet-dry cycle has a more significant influence on strength parameters of geotextile-soil interface. With the increasing shear cycles，the hysteresis curve of geotextile-soil interface expands outward and the interface shear stiffness increases，while the damping ratio decreases. The cyclic shear cycles have limited effects on the strength parameters. Whereas the wet-dry cycles are the main influencing factor on the cyclic shear modulus. Compared to internal friction angle，the cohesion is more significantly affected by cyclic shear history. Meanwhile，repeated wet-dry processes weaken the structural integrity of granite residual soil and enhance the interlocking action of geotextile-soil interface. And the cyclic shear process can cause a decrease in the roughness of geotextile-soil interface，which also explains the phenomenon that the interface shear characteristics between geotextile and granite residual soil presents a trend of first increasing and then decreasing under different wet-dry histories.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[FENG Yuquan1，ZHU Rui1，2，3，ZHOU Feng1，GUO Wanli3，ZHANG Lingka4，WANG Mengling1]]></author>
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<title><![CDATA[Large-strain nonlinear consolidation of dredged sludge yards treated by PHDs considering well resistance effect]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43744.shtml]]></link>
<description><![CDATA[Numerous indoor tests and engineering applications have confirmed the superiority of prefabricated horizontal drains(PHDs) combined with vacuum preloading in treating dredged sludge yards. However，existing consolidation theories for PHDs-treated dredged slurry currently lack consideration of well resistance effects. In this study，based on Gibson's large strain consolidation theory，the well resistance effect of PHDs is considered，and the nonlinear compressibility and permeability of dredged sludge are introduced to establish a consolidation model for the treatment of dredged sludge yards by PHDs combined with vacuum preloading. Solutions for the proposed consolidation model are derived and validated through comparative analysis with existing self-weight consolidation models for ideal PHDs configurations and laboratory test results. Furthermore，the influence of well resistance effects on consolidation behavior is systematically investigated. The results indicate that：Well resistance effects decelerate the dissipation rate of excess pore water pressure，consolidation rate，and settlement deformation，though this retardation diminishes progressively with weakening well resistance；The magnitude of well resistance depends on PHDs installation length，permeability coefficient，laying ratio of the PHDs，and the height of the sludge；Optimization of PHDs layout enhances the consolidation efficiency of dredged sludge. Prioritizing PHDs alignment along shorter repository dimensions effectively mitigates well resistance impacts on consolidation processes. When the laying ratio(?) remains below 40%，increasing &lambda; enhances consolidation rates through improved drainage capacity. Beyond this threshold，however，multi-layer PHDs becomes essential to achieve further efficiency gains.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Changsen，LI Chuanxun]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Testing of fragments ejection characteristics and burst kinetic energy index for different types of coal and rock]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43743.shtml]]></link>
<description><![CDATA[During dynamic failure of coal and rock，a large number of fragments are ejected，and the ejection distance and kinetic energy of these fragments can more intuitively reflect the intensity of the specimen?s failure. This paper proposes a test method for measuring the ejection kinetic energy of coal and rock fragments，and the feasibility of the method is verified through numerical simulation examples. Experimental research is conducted on the fragments ejection characteristics of different types of rocks. Based on this，a classification method for burst liability is proposed based on the burst kinetic energy index. Furthermore，the influence of loading stiffness on the fragments ejection characteristics and burst kinetic energy index of coal is analyzed. The results show that the fragments ejection characteristics of coal and rock specimens vary significantly among different lithologies. The fragments ejection mass proportion and ejection distance of granite and basalt are notably greater than those of sandstone，marble，and coal with lower strength. The stronger the burst liability of the specimen，the greater the fragments ejection distance and kinetic energy. The ejection kinetic energy of the fragments has a positive power function relationship with the uniaxial compressive strength，and a positive linear relationship with both the burst energy index and the residual elastic energy index. The recommended ranges for the burst kinetic energy index for coal with no burst liability，weak burst liability，and strong burst liability are ＜30 J/m&sup3;，30～300 J/m&sup3;，and＞300 J/m&sup3;，respectively. As the stiffness ratio of the testing machine to the specimen decreases，the energy supplied by the testing machine to the coal specimen increases，resulting in an increase in the fragments ejection distance and kinetic energy of the specimen after failure. The burst kinetic energy index has a positive power function relationship with the stiffness ratio. The proposed test method for measuring the specimen fragments ejection kinetic energy and the burst kinetic energy index can effectively evaluate the burst liability and damage intensity of coal specimens.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHAO Tongbin1，2，GUO Lei1，2，YIN Yanchun1，2，XIAO Yaxun3，LI Shihang1，2，GAO Zitong1，2]]></author>
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<title><![CDATA[Research on full-space collaborative support technology of multi-bearing structure reconstructed by strong dynamic pressure crushing soft rock roadway]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43742.shtml]]></link>
<description><![CDATA[In order to solve the complex regional stress caused by excavation of roadway and working face and the maintenance problem of soft rock roadway surrounding rock broken by strong dynamic pressure. Taking the 1570 track stone gate of Daliuchang Coal Mine in Guizhou as the engineering background，numerical simulation，theoretical analysis and field industrial test are used to carry out the research. Based on field investigation and data monitoring，the characteristics of large deformation of surrounding rock and failure of supporting components of 1570 track Shimen are analyzed. The reasons for the poor self-stability of surrounding rock are revealed by water soaking test (combined with XRD analysis) and loosening ring test. The stress distribution law during excavation of 1570 track stone gate is revealed by numerical simulation，and its deformation and failure mechanism is obtained. The ultimate bearing stress of the most dangerous section of the concrete steel arch is obtained by theoretical analysis，and it is determined that the restricted steel pipe filling structure used can limit the large structure movement caused by mining. Numerical simulation is used to analyze the stress distribution and deformation control effect of surrounding rock after reconstituted multi-bearing structure support and without support，and the control principle of full-space collaborative support technology for reconstituted multi-bearing structure is expounded. Through the construction of three-storey strong bearing structure，the shallow and deep surrounding rocks form an integrated high-strength anchor solid bearing structure，and the whole bearing capacity of surrounding rocks and the whole anti-deformation ability of surrounding rocks are mobilized to realize the full-space three-dimensional support system and ensure the stability of the roadway. Based on the above research，the industrial test was carried out underground. The results show that the multi-bearing structure full-space collaborative support technology has a remarkable effect on the deformation control of soft surrounding rock roadway. Compared with the original support，the convergence of the roof and floor and the two sides of the roadway is reduced by 91.67% and 88.33% respectively，and the roadway maintenance cost is saved at the same time，which provides an effective way to control the surrounding rock of the soft rock roadway broken by strong dynamic pressure.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XU Youlin1，WU Shaokang2，ZHOU Bo1，3，ZHENG Wei1，WU Xukun4，ZHOU Ze1，CHEN Zhisong3，ZHANG Jitao5，LI Bin3，YAN Hong6，ZHANG Chuanjiu7]]></author>
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<title><![CDATA[Analysis of failure characteristics in delayed strain-type rock burst simulation test on granite]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43741.shtml]]></link>
<description><![CDATA[Strain-induced rock burst can be classified into instantaneous and delayed types according to rockburst causes. In this paper，a real three-axis unloading and delayed strain-induced rock burst simulation experiment was conducted on granite using a deep-seated rock burst simulation experimental system. Based on the signal collected by the acoustic emission system，quantitative analysis of parameters and waveform was performed. At the same time，high-speed photography was used to record the process of rock burst destruction，and the characteristics of rock surface failure were observed. The occurrence mechanism of delayed strain-induced burst in granite rock was revealed from multiple perspectives. The results indicate that granite occurred severe delayed type rock burst under the special stress loading condition which referred to loading in three directions，unloading one single face and then loading in vertical direction. Before the granite occurred rock burst，the AE ringing counts had an intensive and explosive growth while the AE b-value showed a sudden continuous decline. During the rock burst phase，the proportion of AE signals with high amplitude in low-frequency showed a growth trend，indicating there occured rapid development of large-scale cracks with higher energy release in rock. Based on AE cluster analysis of RA-AF distribution division，it was found that there appeared tensile and shear composite failure，and both the amount of tensile and shear type cracks decreased at first and then had an obvious increase until final decreased. Tensile-shear crack ratio increased and then decreased，remained stable，rose and then dropped again to the lowest value. The fractal of AE ringing count rate presented dense distribution in a short period of time before burst，and had a sudden decrease sharply after the continuous vibration. Compared the warning information of rock burst determined by AE ringing count，b-value，major frequency，RA-AF distribution and AE fractal dimension，the average precursor response coefficients were 1.18%，0.94%，1.50%，1.45% and 0.91% respectively. Hence，the response time for identifying precursors based on the AE major frequency-amplitude and tensile-shear crack amount and ratio were earlier. They could more finely characterize the complexity of AE signals and reveal the rock fracture mechanism. This study can provide reference for revealing the mechanism of delayed type rock burst occurrence and establishing disaster warning methods.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Hongjian1，2，ZHANG Jinran1，LIU Dongqiao3，ZHAO Fei1，3，SHI Xiaoshan2，4，REN Fuqiang5，WANG Chuang1]]></author>
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<title><![CDATA[Similar modelling study on the multi-peak attenuation effect of double tunnels in water-sealed storage cavern under variable amplitude impacts]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43740.shtml]]></link>
<description><![CDATA[In order to study the effect of variable amplitude impacts loading on straight-wall-top-arch double tunnels，similar model of large-size high-strength concrete tunnels were prepared，and a self-developed pendulum impacting system with biaxial stresses was used to carry out impact tests. A super-dynamic information acquisition system was used to record the impact wave and three-directional strain，and digital image correlation was used to characterize the surface strain and the displacement field，so that the mutation characteristics of double tunnels under pendulum impacts were investigated in multiple perspectives. The experiment revealed the following findings：(1) The frequency of the shock wave applied by the pendulum was 100～200 Hz，and there was peak incremental stage，oscillatory decay stage and stable stage in the wave curve，which is a variable amplitude shock wave with amplitude attenuation. The frequency decay amplitude increased from 9.30% to 43.88% under multiple impacts. (2) Five symmetrical cracks appeared in the spandrel and foot of the double tunnels with straight-wall-top-arch，and the wide and deep crack at the inter-cavern-arch-foot was in the form of upward concavity. The damage pattern was mainly affected by the first wave peak of impact force，and the width of the crack at the inter-cavern-arch-foot increased by nearly 6 times under multiple impacts. (3) The strain was mainly tensile strain，with the peak strain of axial direction about 10 400 &mu;? distributed at the inner arch foot，the peak strain of radial direction about 10 600 &mu;? distributed at the inter-cavern-arch-foot，and the peak strain of circumferential direction about 24 800 &mu;? distributed at the outer arch spandrel. The strain increased about 25 times and 5 times in the axial and radial direction under multiple impacts. (4) The vertical strain concentration zones appeared firstly in the inter-cavern-arch-foot within 350 &mu;s. The inter-cavern-arch-foot crack developed from the two inner arch feet，and the strain was stable in the range of 0.002～0.005. The shear strain concentration zones appeared in the outer spandrel and inter-cavern-arch-foot，with the opposite strains occurring in the left and right. The vertical strain peak of the inter-cavern-arch-foot increased by 42.98%. Combined with the crack width and three-directional strain，it was considered that the inter-cavern-arch-foot was the weak part of the double tunnels under the variable amplitude impacts，and the monitoring and supporting should be strengthened in this position.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HU Hongli1，CHANG Suling1，CONG Yu1，2，WANG Xiaoshan1，WANG Zaiquan1，ZHANG Jigang1，2，LI Renjie3，JIANG Hao3]]></author>
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<title><![CDATA[Physical simulation experiments on non-uniform extension of multi-cluster hydraulic fractures under complex fracturing conditions]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43718.shtml]]></link>
<description><![CDATA[Achieving uniform propagation of multi-cluster hydraulic fractures within shale gas reservoir containing natural fracture zones remains challenging. This study developed a physical simulation methodology to model multi-cluster fracturing in specimens containing prefabricated natural fracture zones. The experimental setup for sample preparation and pumping allows for the distribution of liquid into multiple cluster fractures according to a predetermined sequence of extension，with independent monitoring of flow rates for each cluster. Leveraging the engineering-experimental similarity in fracture propagation characteristics，in-situ stress，and geometry，analogous relationships were derived between experimental and engineering parameters. We experimentally investigated the effects of pumping rates(0.825 m3/min and 3.3 m3/min per cluster)，cluster spacing(6 m and 12 m)，and spatial arrangement positions(middle and side clusters) of natural fracture zones on the propagation of multi-cluster hydraulic fractures in field applications. We find that (1) low pumping rates combined with large cluster spacing enhance the uniform propagation of multi-cluster hydraulic fractures in both samples with and without natural fracture zones. Fractures adjacent to natural fracture zones tend to propagate preferentially，thereby inhibiting uniform multi-fracture propagation. (2) High pumping rates and small cluster spacing facilitate the formation of single-cluster branch fractures and promote inter-cluster fracture connectivity. Conversely，low pumping rate and large cluster spacing result in simpler，non-interfering multi-cluster fracture morphologies. When the initiation cluster is adjacent to a natural fracture zone，the morphology of hydraulic fractures exhibits connectivity between hydraulic fractures and natural fracture zones. (3) During multi-fracture propagation，each cluster of fractures sequentially receives fluid inflow，indicating that multiple hydraulic fractures extend in an alternating sequence rather than simultaneously. Clusters situated within fracture zones tend to receive fluid inflow preferentially and connect with natural fracture zones. Consequently，the pump pressure curve exhibits fluctuations prior to reaching the break pressure. (4) Based on the theories of fracture instability extension and stress shadow，this study discusses the mechanisms of single-cluster fracture instability propagation and multi-fracture complexity enhancement. A high pumping rate increases the driving force for fracture propagation，while natural fracture zones decrease fracture resistance，thereby promoting single-cluster fracture instability. Namely，these factors inhibit the uniform extension of multi-cluster hydraulic fractures. Furthermore，a combination of high pumping rate and small cluster spacing intensifies interference between fractures，leading to the generation of complex fractures. Finally，optimization suggestions for the fracturing design were proposed，focusing on achieving uniform propagation of multiple hydraulic fractures near the wellbore while promoting the formation of complex hydraulic fractures in more distant regions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[TAN Peng1，2，3，XING Yuekun2，HAN Taisen2，CHEN Jinlong2，XU Hang2，CHEN Zhaowei1，3]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Refined meteorological early warning for rainfall-induced landslide based on temporal probability model]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43717.shtml]]></link>
<description><![CDATA[The landslide meteorological early warning model based on empirical rainfall thresholds(ERT) always has a low warning accurate，and the temporal probability model(TPM) is expected to make up for this shortcoming. In order to verify this idea，this paper conducted a comparative experiment. First，we used accumulated effective rainfall-duration(EE-D) and rainfall on the day-accumulated effective rainfall in the previous 4 days(R0-AE4) as variables to construct two sets of TPM models，the receiver operating characteristic(ROC) curve and correlation coefficient were then used to evaluate the discriminative and predictive abilities of ERT/TPM. Then，the conditional probability formula was used to couple the spatiotemporal probability of landslides，and a probabilistic landslide meteorological early warning model(P-LEWM) was proposed. Finally，through the way of simulated warning，P-LEWM was compared with the matrix-based landslide early warning model(M-LEWM)，which was constructed with ERT，the results show that：(1) The ERT/TPM constructed by R0-AE4 is more accurate in judging the hazard level of rainfall to trigger landslides，the area under the ROC curve(AUC) increased by 6.8% to 12.5% compared to EE-D；(2) The TPM proposed in this paper can predict the probability of rainfall triggering landslides accurately，the correlation coefficient between the predicted amount of triggering-rainfall and the recorded amount is above 0.83，moreover，the EE-D type TPM is more accurate for heavy rainfall prediction，while the R0-AE4 is more suitable for regular rainfall events；(3) The EE-D type ERT will underestimates the hazard level of long-lasting heavy rainfall triggering landslide，which caused M-LEWM missed lots of landslides which happened in two typical rainfall events in 2018，with an missed rate of more than 50%，while P-LEWM constructed with TPM has a correct alert rate of over 90%；(4) Because of the accurate TPM and reasonable spatiotemporal model coupling method，the correct alert rate of the P-LEWM proposed in this article has been significantly improved compared to M-LEWM，the correct alert rate increased by 20.7% to 26%，the reasonable correct alert rate increased by 15.6% to 28.6%，and the missed alert rate decreased by more than 20.5%.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[SONG Yufei1，LI Xiang2，FAN Wen2，YU Ningyu2，CAO Yanbo2，DENG Longsheng2，TAO Hong3]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Discontinuous gradation effect on large-scale triaxial shear mechanical properties of soil rock mixture]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43716.shtml]]></link>
<description><![CDATA[The geographical distribution of discontinuous graded soil-rock mixtures is extremely widespread，and they are commonly used as backfill materials in subgrade and slope engineering. The discontinuous grading effect exhibited by their shear mechanical properties is a critical factor in the control of compaction quality. First，a discontinuity index is proposed，which can effectively quantify the discontinuous grading characteristics of soil-rock mixtures. Then，large-scale triaxial standard specimens of soil-rock mixtures with different discontinuity indices were prepared，and triaxial shear tests were conducted on the standard specimens using the DJSZ&ndash;150 large-scale triaxial testing apparatus. The influence of and confining pressure on the strength and deformation characteristics of soil-rock mixtures was analyzed. Subsequently，the intrinsic relationships between the parameters of the composite power-exponential model and the deviatoric stress strength， ，and were investigated，leading to the proposal of the CPE model that considers the effects of varying interrupted grain fractions and stress states. Finally，the influence of changes in the discontinuous particle size fractions on the mesoscopic structural characteristics of soil-rock mixtures was explored，elucidating the discontinuous gradation effect on the shear mechanical properties of soil-rock mixtures. The results indicate that under triaxial compression，discontinuous graded soil-rock mixtures generally exhibit strain hardening characteristics，the deviatoric stress strength increases with the rise in ，while the internal friction angle initially increases and then decreases with the increase in . In contrast，the cohesion exhibits an opposite trend；The parameters k，b，and n all exhibit a linear relationship with the . Both k and n show a linear relationship with the ，while b follows a quadratic function relationship with&nbsp; . The improved CPE model not only accurately predicts the strength and deformation characteristics of soil-rock mixtures，but also effectively reflects the influence of discontinuous grading features and stress state on the deformational mechanical behavior of soil-rock mixtures. Different discontinuous particle groups constitute distinct mesostructural characteristics of soil-rock mixtures. Under axial compression loading，an increase in the content of the largest particle group enhances the overall deformational mechanical properties of the soil-rock mixture. However，excessive amounts of large particles can increase the voids between coarse particles，leading to a rise in deviatoric stress strength followed by a decrease.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Chao1，2，3，LOU Aoqing1，YU Jin2，ZHU Dongping3，XU Zan4，CAO Wengui4]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Thermal conductivity and impermeability of spheroidal graphite-bentonite mixture after compaction]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43715.shtml]]></link>
<description><![CDATA[Incorporating flake graphite into bentonite enhances its thermal conductivity but compromises its impermeability. To address this trade-off，spheroidal graphite was selected as a replacement for flake graphite. Thermal conductivity and saturated permeability tests were conducted on spheroidal graphite-bentonite mixtures to study the effects of graphite content and shape on both thermal conductivity and permeability properties of bentonite. The results show that a spheroidal graphite content of approximately 20% markedly enhances the thermal conductivity of bentonite(1.7 W/(m&bull;K))，and ensures the permeability coefficient(9.44&times;10－13 m/s) falls below the buffer layer&rsquo;s threshold of &le;1&times;10－12 m/s. Concurrently，the maximum swelling pressure attained is 5.6 MPa，which falls within the recommended range of the buffer layer(1&ndash;10 MPa). Furthermore，the concept of critical graphite content was introduced，with the critical contents for spheroidal and flake graphite determined to be 27.3% and 16.4%，respectively. At a spheroidal graphite content of 20%，the graphite has not yet formed a skeleton within the mixture，indicating that it remains suspended in the bentonite. Conversely，at a flake graphite content of 20%，a skeleton forms with bentonite filling the spaces within the graphite structure. By combining the microscopic morphology and pore distribution characteristics of graphite-bentonite，this study elucidates why flake graphite enhances thermal conductivity while weakening impermeability. Additionally，it explains the physical mechanism by which spheroidal graphite outperforms flake graphite，providing scientific guidance for improving the operational safety of the repository.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[TAN Yunzhi1，2，WEI Kangxu1，2，ZHU Yu1，2，ZHANG Jinsheng1，2，MING Huajun1，2]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Study on the convergence mode of shield tunnel excavation section adjacent pile foundation]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43714.shtml]]></link>
<description><![CDATA[To reveal the deformation characteristics of soil in the shield tunnels excavation section adjacent piles and establish the convergence model of tunnel excavation section. Model test of shield tunnel excavation adjacent to piles was carried out in this paper. Based on the collected data by the developed monitoring device of tunnel section soil displacement，the soil deformation law of excavation section under different conditions was analyzed，and the loss contour of tunnel section with non-uniform convergence mode is proposed A mapping function expression for the Laurent series of tunnel excavation loss section was established based on the theory of complex functions. The results indicated that the tunnel arch bottom lagged behind that of tunnel vault，and the deformation of the soil around the tunnel section was restrained by the adjacent piles. Comparisons between the calculated values and the measured values were made to check the rationality of the mapping function expression of tunnel excavation loss section.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Qianqing1，2，LIU Jinghang1，2，WANG Maolin1，2，LIU Shanwei1，2]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Study on failure mechanism of slopes induced by the underground coal mining subsidence]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43713.shtml]]></link>
<description><![CDATA[The underground mine workings cause the movement of overlying rock layers and changes in stress fields，leading to the deterioration of rock properties in slopes，which can easily cause disasters such as slope landslides. This study compared the failure process of the underground mine-slope system under different underground mine working conditions using bottom friction tests and numerical simulations. Thus，the failure mode and deformation mechanism of the slope under the influence of underground coal mining subsidence were analyzed. The findings include：(1) the effect of underground coal mining subsidence on slopes mainly includes reducing the integrity and strength of the slope rock mass，changing the inclination angle of the slope rock layer，enhancing the tension effect of the slope surface and causing cracking，and changing the geometric shape of the slope. (2) The fracture mechanism of the overlying rock strata is the gradual bending and collapse of the rock strata towards underground mine workings under the action of gravity. The shape of fracture surface of the rock strata develops in a geese-like pattern with the centerline of the underground mine working as the axis of symmetry in the deep field，and is connected to the tensile fracture in the slope surface in the near-slope field. (3) the mechanism of overlying slope failure induced by underground mine workings can be divided into two types：compression type and traction type. Compression type slope failure usually occurs in the lower slope of mining subsidence，and the process was divided into stages such as overlying rock collapse，subsidence compression，and slope sliding；Traction type slope failure usually occurs on the upper slope of mining subsidence，and the process was divided into stages such as collapse of overlying rock strata，traction and tearing，and slope sliding. (4) the geological structure has a significant impact on the instability and failure process of the overlying slope. When the rock layer of the slope was in a bedding orientation，the fracture surface pattern on both sides of the overlying rock layer rotated towards the dip direction，and the deformation and failure range of the slope induced by the mining subsidence was relatively large；When the rock strata were in a reverse inclined orientation，the effect of the underground mine workings with the same position and burial depth on the displacement of the slope was significantly reduced. The research results can provide reference for the identification of slope disasters in coal mining subsidence areas and the safety prevention of open-pit-underground mining transition projects.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[SUN Shuwei1，YANG Zhaoxi1，JIA Peizhi1，WANG Xiaolong1，LI Guojun2]]></author>
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<title><![CDATA[Development and application of a real-time high-temperature and high-stress true triaxial fracturing test system]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43712.shtml]]></link>
<description><![CDATA[To investigate the fracture initiation and propagation of fracturing in deep oil and gas and geothermal energy reservoir stimulation，a real-time high-temperature and high-stress true triaxial fracturing test system was developed independently，which narrows the gap between laboratory fracturing physical simulation test and the real deep reservoir conditions. This system is primarily used to simulate the fracturing and fracture propagation behavior of 300 mm cubic rock samples in the in-situ environment of deep reservoir. It also monitors and processes parameters such as stress，displacement，pump pressure，flow rate，and acoustic emission signals during the fracture propagation process. The maximum stress in X，Y and Z directions of the system can be loaded to 88 MPa，and the internal temperature of the sample can be heated to 350℃. The intelligent temperature control mode ensures uniform heating of the whole sample，and the maximum pump pressure is 210 MPa when slickwater is used as fracturing medium(120 MPa when supercritical CO2 fracturing). The hydraulic fracturing test of shale and supercritical CO2 fracturing test of granite under high-temperature and high-stress conditions have been completed by using the system. The test results show that the system has high accuracy and good stability. The post-peak fluctuation of pump pressure curve is intensified under high-stress. High-temperature reduces the breakdown pressure and improves the fracture complexity. When supercritical CO2 is used as fracturing medium，the breakdown pressure of granite decreases significantly，the number and energy level of acoustic emission signals weaken，and the fracture complexity increases. The relevant research results can provide theoretical and technical support for the optimization of deep reservoir reconstruction technology.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[GUO Wuhao1，2，GUO Yintong1，2，CHANG Xin1，2，WU Mingyang1，2，HE Yuting1，2，BI Zhenhui1，2，ZHANG Xinao1，2，TENG Shilong1，2，WANG Lei1，2，YANG Chunhe1，2]]></author>
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<title><![CDATA[Study on mechanical properties and compaction quality evaluation of gravel soil subgrade based on impact load method]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43711.shtml]]></link>
<description><![CDATA[The impact loading method is an approach to evaluate the compaction quality of subgrade by applying impact forces and analyzing the resulting response signals. Studying the response mechanism of gravel soil subgrade under impact loading helps to deepen the understanding of the mechanical properties of such subgrades，as well as enhance the comprehension of the principles behind evaluating subgrade compaction quality using impact loading methods. The real working condition of gravel soil sungrade was fully considered，and a dynamic response model for gravel soil subgrade under impact loading was established using the discrete element method. The model parameters were calibrated through triaxial tests，and the model's validity was verified by field experiments. Subsequently，the attenuation characteristics of dynamic stress in the subgrade under different compaction densities were explored and compared with the results obtained from continuous medium theory. A quantitative model relating porosity to the resilient modulus was further developed. The variations in surface response of the subgrade with changes in its properties were analyzed，and finally，the effects of different impact loads amplitudes and plate radius on the effective detection depth were discussed. It is found that：(1) porosity significantly affects the attenuation of internal dynamic stress in gravel soil subgrade，with faster attenuation observed at lower porosity levels；also，the dynamic stress obtained using continuum medium theory is generally lower，with a maximum difference of over 70%；(2) there is a good linear relationship between porosity and resilient modulus of gravel soil subgrade，validating the feasibility of using the impact loading method to evaluate subgrade compaction quality；(3) the plate radius has a significant impact on the effective detection depth of the impact loading method，with effective detection depths within 0.3 m for plate radii of 0.15 and 0.2 m，and between 0.3 and 0.4 m for a radius of 0.25 m.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Mengwei1，2，LU Zheng1，TANG Chuxuan1，2，HU Zhi3，CHAI Shaoqiang4，LIU Yong4]]></author>
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<title><![CDATA[Frost heave characteristics and in-situ testing analysis of carbonaceous slate tunnel surrounding rock in high-altitude cold regions]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43710.shtml]]></link>
<description><![CDATA[To study the frost heave characteristics of transversely isotropic surrounding rock tunnels，methods such as unidirectional freezing tests on saturated carbonaceous slate with different bedding inclinations，theoretical modelling of uneven frost heave force and in-situ testing were used to investigate the frost heave characteristics of the carbonaceous slate tunnel surrounding rock，tunnel temperature field，and distribution characteristics of the surrounding rock frost heave force. The results indicate that：(1) Under unidirectional freezing conditions，the uneven frost heave coefficient of slate gradually increases with the increase of the temperature gradient. The larger the freezing direction and the bedding inclination angle，the stronger the uneven frost heave；(2) The envelope diagram of the freeze-thaw circle of the surrounding rock at the entrance of the Heiqia Tunnel during construction period presents a pear shape，with the lowest temperature and the highest freezing depth at the arch foot，with a maximum freezing depth of 2.97 m；(3) The measured frost heave force of the surrounding rock-structure ranged from 0.08 to 0.63 MPa，with the maximum at the left arch foot and the minimum at the left arch shoulder；(4) Under the condition of considering the relationship between the freezing direction and the inclination angle of slate bedding，the theoretical model of uneven frost heave force in cold region tunnels clarifies the uneven frost heave characteristics of transversely isotropic surrounding rock，which can provide a reference for anti-freezing design in high-risk areas of frost damage in transversely isotropic surrounding rock tunnels in cold regions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LU Hanqing，BAO Weixing，YIN Yan]]></author>
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<title><![CDATA[Analysis of failure characteristics in delayed strain-type rock burst simulation test on granite]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43709.shtml]]></link>
<description><![CDATA[Strain-induced rock burst can be classified into instantaneous and delayed types according to rockburst causes. In this paper，a real three-axis unloading and delayed strain-induced rock burst simulation experiment was conducted on granite using a deep-seated rock burst simulation experimental system. Based on the signal collected by the acoustic emission system，quantitative analysis of parameters and waveform was performed. At the same time，high-speed photography was used to record the process of rock burst destruction，and the characteristics of rock surface failure were observed. The occurrence mechanism of delayed strain-induced burst in granite rock was revealed from multiple perspectives. The results indicate that granite occurred severe delayed type rock burst under the special stress loading condition which referred to loading in three directions，unloading one single face and then loading in vertical direction. Before the granite occurred rock burst，the AE ringing counts had an intensive and explosive growth while the AE b-value showed a sudden continuous decline. During the rock burst phase，the proportion of AE signals with high amplitude in low-frequency showed a growth trend，indicating there occured rapid development of large-scale cracks with higher energy release in rock. Based on AE cluster analysis of RA-AF distribution division，it was found that there appeared tensile and shear composite failure，and both the amount of tensile and shear type cracks decreased at first and then had an obvious increase until final decreased. Tensile-shear crack ratio increased and then decreased，remained stable，rose and then dropped again to the lowest value. The fractal of AE ringing count rate presented dense distribution in a short period of time before burst，and had a sudden decrease sharply after the continuous vibration. Compared the warning information of rock burst determined by AE ringing count，b-value，major frequency，RA-AF distribution and AE fractal dimension，the average precursor response coefficients were 1.18%，0.94%，1.50%，1.45% and 0.91% respectively. Hence，the response time for identifying precursors based on the AE major frequency-amplitude and tensile-shear crack amount and ratio were earlier. They could more finely characterize the complexity of AE signals and reveal the rock fracture mechanism. This study can provide reference for revealing the mechanism of delayed type rock burst occurrence and establishing disaster warning methods.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Hongjian1，2，ZHANG Jinran1，LIU Dongqiao3，ZHAO Fei1，3，SHI Xiaoshan2，4，REN Fuqiang5，WANG Chuang1]]></author>
<pubDate><![CDATA[]]></pubDate>
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<title><![CDATA[Experimental study on the mechanical properties of sandstone with different numbers of fractures before and after grouting]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43708.shtml]]></link>
<description><![CDATA[To investigate the influence of fracture number on the strength of rock before and after grouting，as well as the crack propagation patterns，an experimental study was conducted on the mechanical properties of sandstone with different numbers of fractures before and after grouting. The study combined XTDIC(Digital Image Correlation) and acoustic emission systems to examine crack propagation patterns from both macroscopic and microscopic perspectives. The experimental results showed that：(1) With an increase in the number of fissures，the time of the compaction stage in the stress-strain curve became shorter，and the crack development and propagation stage commenced earlier. The strength weakening coefficient exhibited a power function growth trend with the number of fissures，and the average compressive strength decreased by 15.82% to 53.32%. The strength recovery coefficient under a 1：1 water-cement ratio slurry showed an exponential decrease with the number of fissures，improving by 6.76% to 29.27% compared to the ungrouted state，reaching 60.34% to 89.88% of the original rock strength；(2) The number of fissures significantly impacted the crack initiation stress，which increased after grouting. The ratio of crack initiation stress to peak stress before and after grouting decreased with the increase in the number of fissures，showing a downward opening quadratic function relationship；(3) The crack propagation patterns before and after grouting with different numbers of fissures exhibited certain similarities. Cracks primarily developed from the fissure tips and connected prefabricated fissures before and after grouting，causing rock bridge penetration and predominantly tensile failure；(4) The AE ringing count and cumulative ringing count significantly increased with the number of fissures. Grouting could only improve the rock's overall integrity to a certain extent and suppress stress concentration at the tips but could not effectively prevent crack propagation and interaction；(5) Theoretical analysis indicated that the stress intensity factor after grouting was lower than before grouting，and KⅠgrouted＜KⅠ and KⅡgrouted＜KⅡ，suggesting that the stress at the fissure tips reduced after grouting，thereby enhancing the rock's strength. This was validated through numerical simulations.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[CHEN Juntao1，2，3，YU Junjian1，2，LI Guo1，3，XU Changlong1，2，FAN Mingjin1，3，WANG Yunhao1，3，JIAO Bin1，3]]></author>
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<title><![CDATA[Study on dynamic characteristics of rock discontinuities under high cyclic shear rate]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43690.shtml]]></link>
<description><![CDATA[The natural occurrence of numerous discontinuities in rock masses makes them prone to significant displacements and friction degradation under external dynamic forces，thereby increasing the risk of instability. Therefore，in order to explore the mechanical properties of jointed rock mass under the action of cyclic dynamics，this study focuses on natural red sandstone and explores the shear mechanical characteristics of rock discontinuities under cyclic shearing，considering the dynamic properties of rock masses by setting a high shear rate. The evolution of shear stress and normal displacement during cyclic shearing is revealed，and a peak shear strength prediction model for structural planes，incorporating the number of cyclic shearing cycles，is established based on plastic work theory. The results show that：(1) The applied cyclic shear rate(2 mm/s) reaches the dynamic range，and compared to quasi-static direct shear tests，this rate better simulates the shear mechanical behavior of discontinuities under dynamic conditions. (2) Under cyclic shearing，the number of cycles，type of discontinuities，and normal stress significantly affect the evolution of shear stress on the discontinuities. Normal displacement exhibits clear patterns at shear displacements of 0 mm and &plusmn;5 mm. With an increasing number of cycles，normal displacement gradually decreases，indicating a reduction in dilatancy and an increase in compaction. (3) A peak shear strength prediction model that considers the number of cyclic shear cycles is established，with an overall error of around 10% compared to actual conditions，demonstrating good applicability. The research findings provide theoretical support for the safety and stability assessment of rock engineering under dynamic disturbances.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Qingzhao1，2，TONG Zehao1，2，SHI Zhenming1，2，XIE Kelu1，2，3，LUO Zejun1，2，4]]></author>
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<title><![CDATA[Rock burst intensity grading prediction based on the combination of PCA，CBLOF and SVMSMOTE algorithms]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43689.shtml]]></link>
<description><![CDATA[To reduce the correlation between feature parameters in rock burst sample data，remove outliers，and balance the number of various rock burst levels in the dataset，a method combining PCA(principal compo-nent analysis)，CBLOF(cluster-based local outlier factor)，and SVMSMOTE(support vector machine synthetic minority over-sampling technique) is proposed to enhance the quality of the rock burst database. Initially，343 rock burst cases from both domestic and international sources were collected to build the original rock burst da-taset. PCA is employed for dimensionality reduction，CBLOF is used to eliminate outliers within each rock burst level，and SVMSMOTE synthesized new minority samples near the boundaries of each rock burst level. The processed and original rock burst databases were then trained using six different machine learning models to vali-date the effectiveness of the PCA，CBLOF，and SVMSMOTE combination. Results show that the accuracy of models trained on the processed database improved significantly：AdaBoost by 29%，CatBoost by 28.5%，LightGBM by 34%，GradientBoosting by 28%，ExtraTrees by 26.5%，and RandomForest by 24%，compared to models trained on the original database. Therefore，processing the rock burst database using the combined PCA，CBLOF，and SVMSMOTE algorithms effectively enhances the quality of the database and improves the performance of machine learning prediction models.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YAO Nan1，2，Zhang Yili1，LIU Yang1，2，YE Yicheng1，2，LUO Xiaobing3，FENG Jie3，HUANG Zhaoyun4]]></author>
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<title><![CDATA[Effect of bedrock-surface inclination on characteristics of trailing edge crack in soil landslide sliding along the bedrock surface]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43688.shtml]]></link>
<description><![CDATA[The position of the trailing edge crack typically corresponds to the boundary of the trailing edge in a soil landslide. This paper aims to explore the effect of bedrock-surface inclination on the characteristics of the trailing edge crack in a soil landslide sliding along the bedrock surface. To achieve this，twelve laboratory tests on trailing edge cracks in soil landslides along the bedrock surface are conducted. A theoretical approach for calculating the position of the trailing edge crack is then proposed. The theoretical approach is subsequently applied to calculate the positions of trailing edge cracks in twelve laboratory landslides and two field landslides. The results show that the inclinations of the trailing edge cracks in the twelve laboratory tests range from 63.7&deg; to 78.1&deg;. As the bedrock-surface inclination increases，the failure mode of the trailing edge crack transitions from predominantly tensile failure to predominantly shear failure，resulting in a corresponding decrease in the inclination of the trailing edge crack. The proposed theoretical approach treats the landslide as a stressed body，with the slip surface divided into two parts：the bottom slip surface and the steeper trailing edge crack surface. The bottom slip surface exhibits tensile failure. In contrast，the trailing edge crack surface exhibits tensile failure and shear failure at positions near and far from the slope surface，respectively. For both laboratory and field landslides，the overall deviation of the trailing edge crack positions calculated by the theoretical approach from the measured positions is not significant. The results of this study help to accurately locate the trailing edge crack in the landslide.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[RAO Yunkang1，2，YANG Tao2，CHEN Huailin2，ZHANG Zhe2]]></author>
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<title><![CDATA[Experimental study on the dynamic responses of pile-raft foundation of high-rise building in liquefiable site]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43687.shtml]]></link>
<description><![CDATA[The objective of the current investigation is to delineate the dynamic response mechanism of piled raft foundation supporting high-rise structures in the context of liquefiable sandy soil under the influence of intense seismic activity. Within the scope of this study，a scaled-down model representing the integrated system of saturated sand strata，piled raft foundation，and high-rise edifice has been meticulously designed and fabricated. Utilizing the centrifuge shaking table apparatus，dynamic response assessments under varying degrees of ground motion intensity have been conducted. The study primarily concentrates on the analysis of soil acceleration responses，variations in excess pore&nbsp; water press ratio，dynamic behavior characteristics of high-rise structural systems，and the underlying dynamic response patterns of pile-raft foundations. Furthermore，the investigation delves into the interrelation between soil liquefaction and the dynamic response of the pile-raft foundation system of high-rise buildings. The empirical findings indicate that the piled raft foundation of high-rise buildings exacerbates the depth of soil liquefaction to a certain degree，with the dissipation of pore pressure occurring at a leisurely pace amidst the pile clusters. The amplitude of acceleration response spectra diminishes with the progression of soil depth. During the occurrence of minor seismic events，the acceleration of the raft tends to escalate，whereas，in the case of major seismic events，the acceleration response of the raft exhibits an initial increase followed by a subsequent decrease. As the peak acceleration of seismic waves intensifies，the maximum bending moment experienced by the pile shafts progressively diminishes，with the upper bending moment of the central pile being more pronounced. Moreover，the maximum bending moments of corner piles，side piles，and central piles are observed at the interface between the sandy soil layers. The liquefaction of the foundation soil provides a damping effect for the superstructure to a certain extent.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Yurun1，SHAO Dingsong1，LI He1，WANG Yongzhi2]]></author>
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<title><![CDATA[Physical model tests on landslide dam caused by rock-ice avalanches]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43686.shtml]]></link>
<description><![CDATA[The landslide dams formed by rock-ice avalanches are a common geological hazard in the southeastern Tibetan region of China. This study investigates the effects of ice content and spatial location of ice-rock materials on the formation morphology，dam failure process，and stability of debris dams through large-scale flume experiments. The results indicate that ice debris enhance the mobility of debris material，leading to increased blockage in the riverbed. Ice debris are influenced by particle segregation，primarily accumulating on the upper part of the landslide dams and on the opposite bank of landslide. Under the impact of water flow，ice debris within the landslide dams melt rapidly，thereby increasing the porosity of the dam body and weakening the resistance to erosion，resulting in the formation of deeper and wider breach outlets and accelerating the dam failure process. Additionally，a dimensionless stability evaluation method( ) for landslide dams containing ice is proposed. Evaluation results demonstrate a linear decrease in the stability of the landslide dam with increasing ice content.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Darui1，FAN Gang1，LIN Ziyu1，LI Congjiang1，YANG Xingguo1，2，ZHOU Jiawen1，2]]></author>
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<title><![CDATA[Theoretical and experimental study on the spalling law of tunnels subjected to underground explosion]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43685.shtml]]></link>
<description><![CDATA[Spalling is a primary failure mode observed in underground tunnels exposed to explosion waves. The spalling laws of underground tunnels in homogeneous hard rock and fractured rock masses were analyzed using a one-dimensional wave model and a block instability model，respectively. The calculation formulas for spalling block size，spalling velocity，and critical scaled distance for spalling under different conditions were obtained. Existing explosion tests of underground tunnels were analyzed using the proposed theoretical methods. To obtain real spalling data and verify the calculating theory，a prototype explosion experiment was conducted on a U-shaped tunnel in granite. The experiment revealed the spalling damage phenomenon of the tunnel at a scaled distance of 1.03 m/kg1/3，and measured the peak particle velocities at the tunnel top，the ejection velocities of spalling blocks，and the irreversible displacements of the tunnel wall. The measured results are in good agreement with the theoretical calculation results，which verified the scientific reliability of the theoretical method.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Jie，XU Tianhan，FAN Pengxian，LI Gan，JI Yuguo，ZHAO Yuetang]]></author>
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<title><![CDATA[Study on cyclic shear mechanical properties of anchoring systems containing anchor cable，anchoring agent and surrounding rock]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43684.shtml]]></link>
<description><![CDATA[The interfaces between anchor cable，anchoring agent and the surrounding rock are weak areas in anchoring systems. Focusing on the debonding failure characteristics under cyclic disturbance action，this study established an equivalent shear mechanics model for the anchoring system and conducted cyclic shear tests. The influences of rock lithology，normal load (Fs)，cyclic shear displacement amplitude (ud) and cycle number (N) on the shear mechanical properties of the anchoring system were studied. The experimental results indicate that the anchoring system experiences progressive accumulation of damage during the cyclic shear stage，with the maximum shear force (Fhpeak) generally presenting a decreasing trend with N. As ud increases，the location of the maximum shear force of the anchoring system gradually transfers from the direct shear stage to the cyclic shear stage. The peak shear force (Fhmax) and residual shear force (Fhres) decrease by 28.46%‐54.13% and 21.22%‐49.25% respectively. An increase in the rock strength and normal load strengthens the shear resistance characteristics of the anchoring system. In the cyclic shear stage，the sustained wear and degradation at the interface result in a more pronounced normal shear contraction within the anchoring system. Conversely，in the direct shear process，the climbing effect of the through fracture plane leads to gradual prominence of the normal shear dilation. The overall shear contraction of the anchoring system is gradually enhanced with an increase in ud and Fs，while weakened with the increasing rock strength. Three typical shear failure modes of the anchoring system are identified：internal shear fracture through the coal matrix，debonding failure and fracture of the anchoring agent-sandstone interface，and debonding and slip of the anchor cable-anchoring agent interface in the limestone anchoring system. The whole process of shear fracture surface formation and debonding failure evolution of the anchoring system is discussed based on the digital photography.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YIN Qian1，2，TAO Zhigang2，ZHU Qiang1，HE Manchao2，WANG Fengnian3，WU Jiangyu1，PU Hai1，REN Shulin2，LV Zhongyu4]]></author>
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<title><![CDATA[Study on the correlation between rock?s mineral compositions and macro-micro friction properties]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43683.shtml]]></link>
<description><![CDATA[Mineral compositions is an important factor affecting the macro-micro friction mechanical properties of rock. The macro-micro friction properties of sandstone are studied based on direct shear and nano-scratch tests，the variations of mineral compositions before and after shearing are analyzed using X-ray diffraction，the macro-micro friction coefficients of rock，different minerals and interfaces are statistically obtained，and the friction correlation mechanism between the two is established. The results show that the proportion of hard-phase minerals in the total amount of powder increases after shearing，the proportion of soft-phase minerals decreases. The scratch depth and friction force of hard-phase minerals remain stable，those of soft-phase minerals vary significantly. Statistical analysis of the probability distribution curve of the friction coefficient reveals that each mineral and interface exhibit a single-peak Gaussian distribution. Combined with the analysis of macro-micro friction mechanisms，it is found that the macro friction force of sandstone is influenced by surface asperities and the wear between different minerals，the friction force of hard-phase minerals mainly depends on their inherent properties，the friction force of soft-phase minerals and interfaces is affected by their inherent properties，plastic flow and the extrusion of surrounding minerals. By further quantifying the relationship between macro-micro friction coefficients，the hard-soft phase interface contributes the most to the macro friction coefficient with 52.1%. The research results of the macro-micro friction properties can provide a theoretical foundation for revealing the mechanism of cross-scale friction mechanics.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HUANG Man1，2，LU Mengyi1，2，WU Yuewei1，2，LIU Dan3，ZHANG He1，2，HE Zhihai1，2]]></author>
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<title><![CDATA[Reliability analysis of slopes from sparse measurements considering sites similarity]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43682.shtml]]></link>
<description><![CDATA[This paper proposes a hierarchical Bayesian method(HBM) with MCMC to address the challenges of large uncertainty in geotechnical statistics，inaccurate probability distribution of geotechnical properties，and unreasonable reliability analysis of slopes due to limited geotechnical experimental data. The HBM effectively integrates measurements from multiple similar geotechnical sites and combines them with the limited measurements at the target site. This integration allows for a reasonable characterization of the probability distribution of geotechnical parameters for the target site under small sample conditions. The effectiveness of the proposed method is validated using real datasets from several loess sites in the northern Shaanxi Province，China. Furthermore，a reliability analysis of a loess slope is conducted to demonstrate the practical application of the HBM. The results indicate that the proposed HBM significantly reduces the failure probability of the loess slope from 11.6% to 4.8%. Additionally，a comprehensive set of numerical examples is used to explore and verify the accuracy of the HBM compared to traditional methods. The results show that the HBM improves the accuracy of geotechnical statistics by 33% to 53% and reduces uncertainty by approximately 19% to 53% compared to conventional Bayesian methods that do not fully utilize the information from multiple similar geotechnical sites.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XU Ling，WANG Wenlong，ZHAO Tengyuan]]></author>
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<title><![CDATA[Mechanism of hydraulic fracture propagation in hot dry rocks under the influence of thermal stress and natural fractures]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43681.shtml]]></link>
<description><![CDATA[Clarifying the hydraulic fracture propagation mechanism of hot-dry-rock (HDR) reservoirs under the influence of thermal stress and natural fractures is of positive significance for effectively guiding the hydraulic fracturing construction design and efficiently developing geothermal energy. In this paper，a high-temperature true triaxial hydraulic fracturing simulation experiment system developed independently is applied to perform high-temperature true triaxial hydraulic fracturing experiments on granite specimens，and the effects of temperature changes on the rock fracture are analysed. Then a 3D thermo-hydro-mechanical coupling fracture propagation simulation model is established based on the continuum&ndash;discontinuum element method，and its accuracy is verified by the 3D fracture propagation theoretical model and the high-temperature hydraulic fracturing experiments. And the influence of thermal stress and natural fractures on hydraulic fracture propagation patterns in HDR reservoir is investigated by numerical simulation. The results show that the induced thermal stress generated by injecting cold water can reduce the reservoir fracture pressure and fracture extension pressure，increase the fracture width and decrease the fracture length. As the temperature of the rock sample increases，the induced thermal stress increases significantly，and the rock fracture pressure of the experiments and the numerical simulations both decreases significantly. Considering the effect of induced thermal stress，the hydraulic fracture can active the natural fractures even at large horizontal geostress differences and approximation angles. Compared with the HDR reservoir without natural fractures，the stimulation reservoir volume of the reservoir with 200 randomly distributed natural fractures increases by 63.8%. With the reservoir thermal expansion coefficient increases，the effect of thermal stress becomes more and more obvious，and even secondary fractures are generated in the direction perpendicular to the main fracture surface，and the stimulation reservoir volume increases significantly.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[GUO Tiankui1，WANG Jiwei1，2，3，ZHAI Cheng2，3，CHEN Ming1，DAI Caili1，QU Zhanqing1，ZHANG Bo1]]></author>
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<title><![CDATA[Development and application of multi-field coupling test system for deep coal-rock dynamic disaster]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43680.shtml]]></link>
<description><![CDATA[Currently，the academic community has yet to establish a unified set of conditions applicable to the mechanism of rockburst. In this study，the authors independent developed an dynamic disturbance multi-field coupling(DDMFC) tests system designed to explore dynamic disasters in deep coal and rock formations. Using a &ldquo;stress-temperature-seepage-disturbance&rdquo; DDMFC approach，the authors examined various factors influencing rockburst phenomena. They conducted a series of systematic tests，including single-field experiments(such as uniaxial and conventional triaxial tests)，and dual-field experiments (including &ldquo;confining pressure-seepage&rdquo; and &ldquo;confining pressure-disturbance&rdquo; comparisons). These experiments not only validated the reliability of the self-developed test equipment but also laid a strong theoretical foundation for accurately identifying and diagnosing factors that induce rockburst under DDMFC conditions. The key findings from these tests are as follows：(1) The DDMFC tests system in deep coal and rock formations can perform uniaxial and triaxial compression tests，cyclic loading and unloading tests，as well as permeability tests，under triaxial coupling conditions. These tests cover a range of conditions，including normal and high temperatures，as well as low-frequency dynamic disturbances，allowing the system to meet the test requirements of complex stress paths for various engineering rock masses. The results obtained from these tests are reliable. (2) In DDMFC tests，the authors analyzed energy indicators during the loading process to characterize the damage process in coal samples. When the confining pressure of the coal samples increased from 0 to 4 MPa，the average peak strengths measured were 14.75 and 62.67 MPa，respectively. The cumulative energy under single-field conditions was 24.3&times;105 mV&bull;ms，while under dual-field conditions，it reached 52.0&times;105 mV&bull;ms. This indicated that disturbances enhanced the strength of the coal mass and exacerbated damage levels. (3) The damage types of coal samples were classified using the RA/AF index. Under triaxial stress conditions，the complexity of damage types increased across different physical fields，with shear failure remaining the dominant mode of damage. This demonstrated that the confining pressure significantly influenced the strength of coal samples under varying physical field conditions，and the discrete nature of the monitoring data increased notably under multi-field coupling effects. (4) Given that real-world environments involve the superimposition of dynamic，static，and seepage forces，the complexity of accurately predicting and preventing rockburst increases significantly. The results of this analysis are crucial for advancing the development of rockburst prevention and control systems under complex stress conditions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XU Huicong1，2，LAI Xingping1，2，SHAN Pengfei1，2，ZHANG Shuai1，YANG Pan1，WANG Huachuan1，3，LI Jieyu1，2，LI Wei4]]></author>
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<title><![CDATA[An advanced geological forecast method of tunnels based on multi-source data fusion of full-process information]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43679.shtml]]></link>
<description><![CDATA[The existing advanced geological forecast methods consider the integration of multiple source information，but still face issues such as limited participation of geological information and incomplete sources of integrated data. This study proposes a multi-source data fusion method for tunnel advanced geological forecast based on the full construction process information. It screens and establishes a full-process indicator system，containing 7 major categories and 232 indicators，and a targeted indicator system for unfavorable geological problems. Besides，A mapping conversion method of ITV-IRV(indicator test value and indicator risk value)，which combine quantitative indicator segment functions，semi-qualitative indicator node interpolation，and qualitative indicator threshold classification，is proposed，as well as a data area segmentation method. Finally，Analytic Hierarchy Process and Huber Weighting method are used for weight analysis. Fuzzy Fusion Theory and so on methods are applied for data fusion and obtaining the risk probabilities of unfavorable geological problems. The results show：(1) The full-process indicator system and unfavorable geological problem indicator system provide comprehensive advanced geological forecast indicators. (2) The ITV-IRV mapping conversion method，data area segmentation method and indicator weight analysis methods，enable data normalized across indicators and be ready for multi-source data fusion. (3) The multi-source data fusion operation，combining mathematical geological logic，Fuzzy Fusion Theory，and other fusion methods，can accurately and effectively obtain the risk probabilities of unfavorable geological problems. (4) Engineering applications demonstrate that the proposed advanced geological forecast method improves forecasting accuracy，enhances comprehensiveness，increases efficiency，and effectively guides construction.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Shishu1，WANG Peng2，ZHANG Kai1，3，XIAO Huabo1，XUE Yiguo3，CHEN Weitao1，RAN Congyan1]]></author>
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<title><![CDATA[Comparative study on shear mechanical properties and failure mechanisms of rough joints under CNL and DNL boundary conditions]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43677.shtml]]></link>
<description><![CDATA[The dynamic loads induced by excavation disturbance and earthquake significantly influence the deformation and instability of jointed rock masses. To investigate the shear mechanical properties of rock joints under dynamic normal load，a series of shear tests were conducted on red sandstones under dynamic normal load(DNL) and constant normal load(CNL) boundary conditions. The shear test results，i.e.，shear strengths，failure modes，acoustic emission characteristics and failure mechanism obtained under the two boundary conditions were comparatively analyzed. The shear test results show that the shear stress reflects was lagged the dynamic normal stress and the phase offset was positively correlated with the initial normal stress and joints roughness. The influence of dynamic normal load on peak shear strength depended on the failure mode. When the primary failure mode was climbing and dilation，the peak shear strength was increased by the dynamic normal load；conversely，when the failure mode showed up as dominated by the shearing and fracturing of asperities，the peak shear strength was decreased. The dilation was significantly confined by the dynamic normal load，which exacerbated the wear on joints surface and the degradation of asperities. The acoustic emission monitoring results indicated that the dynamic normal load intensified the damage degree at the initial shear stage. It increased the proportion of shear fractures whereas decreased the proportion of tensile fractures. Based on obtained test results and revealed shear mechanism，a dilatancy model was deduced considering the influence of the dynamic normal load. Finally，a model for predicting the peak shear strength of joints under DNL conditions was proposed and it was validated to have a satisfactory prediction accuracy.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Xiaobo1，2，YI Le1，2，YAO Chi1，2，MA Yongli1，2，YANG Jianhua1，2，JIANG Qinghui3，ZHOU Chuangbing1，2]]></author>
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<title><![CDATA[Numerical implementation of the elastoplastic constitutive model based on the improved smoothed GZZ criterion into ABAQUS]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43675.shtml]]></link>
<description><![CDATA[The Smoothed Zhang-Zhu(GZZ) criterion，which is proposed in recent years，is a three-dimensional strength criterion for rocks. It can describe the nonlinear strength characteristics of rock materials reasonably and reliably. However，only a few finite element software are equipped with this criterion，and most of the existing constitutive model programs based on the GZZ criterion are carried out in the principal stress space，which is difficult to apply in ABAQUS. In addition，the current numerical simulations based on the smoothed GZZ criterion often use the correlated ideal elastoplastic model，ignoring the plastic deformation characteristics and strength nonlinearity of the rock. In this paper，the plastic potential function of the smoothed GZZ criterion is improved，and a numerical implementation method of the constitutive model based on the smoothed GZZ criterion in the general stress space is proposed，which avoids the principal stress transformation problem. At the same time，a calculation method considering the expansion characteristics and strength changes of rock is given. Finally，the calculation of the constitutive model is realized by writing the UMAT subroutine in ABAQUS，which is verified by three examples，and the model，which is calculated in the general stress space，can reflect the rock expansion characteristics and strength nonlinearity，and the numerical solution is consistent with the analytical solution and the model test results，which proves the model has high calculation accuracy.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WU Wenjie1，WU Wei1，2，ZOU Yulin3，GU Hao4，ZHU Hehua1，2]]></author>
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<title><![CDATA[limit equilibrium variational method for stability analysis of fractured rock slopes under generalized h-b strength criterion]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43674.shtml]]></link>
<description><![CDATA[Due to the complex nonlinear characteristics often exhibited in the shear failure behavior of rock mass，the existing theoretical methods face challenges in analyzing the stability of fractured rock slopes. In this study，the differential control functions of the slip surface and its stress are established using the variational method. The calculation formula for the factor of safety(FOS) of the slope and the unknown variable in the stress function for the slip surface are derived by applying the limit equilibrium(LE) principle. To address the interdependent relationship among the shape of the slip surface，the normal stress on the slip surface，and the instantaneous shear strength parameters under the generalized Hoek-Brown(H-B) strength criterion，a discrete calculation approach and a coupled correlation solution strategy are implemented to directly tackle the difficulties introduced by the nonlinear strength criterion. On this basis，the global vraiational extremum problems are treated as multiple deterministic boundary variational extremum problems. With slip surface parameters as optimization variables and the minimum slope FOS along with variational extreme conditions as optimization objectives，a multi-objective optimization genetic algorithm was employed to accurately and efficiently search for the critical slip surface of the slope. This approach eliminates the moving boundary transboundary condition and strictly adheres to the variational control conditions. The feasibility and practicability of the proposed method are verified through comparisons with several examples. This research contributes to the advancement and refinement of the LE theory for slope stability and provides an effective computational framework for the stability analysis of fractured rock slopes under complex conditions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[DENG Dongping，XU Ruidong，PENG Yihang]]></author>
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<title><![CDATA[Study on the mechanism and preliminary application of efficient directional rock breaking using a coal-based solid waste non-explosive expansive agent#br#]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43672.shtml]]></link>
<description><![CDATA[In search of a safe and efficient method for fracturing coal and rock masses without using explosives and with controllable crack propagation direction，this study proposed an efficient directional rock-breaking technology utilizing a coal-based solid waste non-explosive expanding agent，i.e.，instantaneous expander with a single fracture surface(IESFS). First，directional rock-breaking experiments with an IESFS were performed with the aid of a self-developed experimental system. Besides，the damage-displacement evolution in the rock-breaking process of the IESFS was studied through numerical simulation. Furthermore，the IESFS was applied to directional roof fracturing in an underground coal mine. The research findings are as follows：(1) The IESFS utilizes an electrical current to activate the fuse，which in turn triggers the coal-based solid waste expanding agent to generate high-pressure gas within 0.05-0.5 seconds. Such high-pressure gas serves to efficiently break the rock. (2) Conventional blasting generally induces rock fracturing in a &ldquo;line-to-plane-to-solid&rdquo; pattern. In contrast，the IESFS fractures the rock in a &ldquo;point-to-line-to-plane&rdquo; pattern，that is，it exerts forces at a point，initiates rock fracturing on a line，and complete rock fracturing on a plane. (3) When used to fracture concrete specimens，the IESFS induces the formation of a high-pressure gas jet with concentrated energy at points，enabling precise control over the direction of fracture propagation and the number of fractures. (4) The damage in the cutting direction is significantly greater than that in the non-cutting direction，the former being 7.92 times greater than the latter. (5) After the IESFS is applied to in-situ fracturing of the roof，the directional roof cutting effect was superior. Additionally，its cutting rate is 11% higher than that of conventional shaped charge blasting，which is indicative of its more powerful performance. The research findings are expected to provide valuable insights and references for exploring novel non-explosive directional rock-breaking methods.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Quan1，2，HE Manchao1，2，GUO Shan2，YANG Rongzhou3，CHEN Kai1，WANG Chao2]]></author>
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<title><![CDATA[Mechanisms of rock burst instability in deep coal roadway with high three-way stress difference area]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43669.shtml]]></link>
<description><![CDATA[Addressing the issue of rock bursts and instability in deep coal roadways with high three-way stress differences，this study uses theoretical analysis and numerical simulations，combined with engineering case studies，to reveal the mechanisms of rock bursts and instability in such area. Based on the Mohr-Coulomb criterion，the definition of the three-way stress difference is modified to ，providing a quan-titative damage criterion for coal body units. High three-way stress differences in deep coal mines are categorized into horizontal tectonic stress type and vertical stress type based on their origins. After roadway excavation in these high-stress difference areas，coal rib cracks develop and experiences significant damage. In conditions of high three-way stress differences，the cracks in the coal body of the roadway become more extensive and develop rapidly，with larger displacements and faster rates of destruction. The peak value of the three-way stress difference，which is distributed radially around the surrounding rock，defines the interface between the failure and non-failure area. The failure area exerts a suppressive effect on the non-failure area by increasing the three-way stress differ-ence. in the non-failure area significantly influences the stability of the coal roadway. A stability parameter，denoted as Ss，is introduced to assess the stability of the surrounding rock of coal roadway or unexcavated coal configu-rations. This parameter indicates the stability of the coal roadway. When the surrounding rock?s Ss is less than the[Ss] of the non-failure area boundary，accumulated deformation in the non-failure area drives coal from the failure area towards the roadway，causing instability. When Ss decreases sharply，the non-failure area experience rapid failure and significant deformation accumulation，which drives the coal body in the failure area to undergo rock burst. This mechanism is confirmed through an analysis of a rock burst incident in the high three-way stress area of the coal seam above the coal pillar at Huafeng coal mine.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Guolei1，LIANG Wenzhao2，3，MA Qiufeng1，WANG Zedong4，QU Xiaocheng5]]></author>
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<title><![CDATA[Study on compressive strength test and estimation model of fiber reinforced loess]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43668.shtml]]></link>
<description><![CDATA[To investigate the compressive strength characteristics of fiber-reinforced loess and develop a corresponding strength estimation model，unconfined compressive strength tests were conducted to analyze the effects of varying fiber content，fiber length，fiber fineness，and moisture content on the compressive strength of reinforced loess. Combined with scanning electron microscopy(SEM) tests，the reinforcement mechanism and macro-mechanical properties of the fiber-reinforced soil were analyzed from a microscopic perspective. The test results indicate that the compressive strength of fiber-reinforced loess increases with higher fiber content，greater fiber length，and reduced fiber fineness；within the studied fiber length range of 10～40 mm，fiber reinforcement was effective. When fiber content is below a critical level，increasing fiber length and reducing fiber fineness further enhance soil reinforcement. Based on the test data，a reinforcing parameter Ir was developed to quantitatively evaluate the reinforcement effect，and a strength estimation model for fiber-reinforced loess was established. This model provides an accurate estimation of the compressive strength of fiber-reinforced loess，as verified through comparison with test results，showing high prediction accuracy and practical applicability.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[CHU Feng1，ZHU Yuguang1，SHAO Shengjun2，CHEN Ting1，ZHANG Dandong1，WU Yunchao1，CHEN Cunli2]]></author>
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<title><![CDATA[Experimental investigation on dynamic mechanical properties and deformation failure mechanism of anchored coal samples#br#]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43645.shtml]]></link>
<description><![CDATA[The dynamic mechanical properties of anchored bodies，which determine the stability of anchor bearing structures，is the scientific basis for further revealing the deformation and failure mechanism of anchor bearing structures under impact dynamic loads. In this study，the dynamic mechanical properties and deformation failure processes of three types (unanchored，end-anchored，and fully-anchored) of specimens subjected to dynamic impact loads under varying pre-tightening forces were investigated with the aid of the split Hopkinson pressure bar(SHPB) technique. Based on the test results，the dynamic stress-strain curves，dynamic strain field evolution characteristics，and anchor rod axial force characteristics of anchored coal specimens were yielded. Furthermore，the interactions among anchor rods，anchoring agents，and pre-tightening forces during impact failure were analyzed，and the dynamic deformation and failure mechanism of anchored coal specimens was disclosed. The following beneficial results were obtained：(1) Under dynamic impact loads，the stress-strain curves of anchored specimens exhibit significant elastic-plastic behaviors，and their dynamic strength and average peak strain values both grow with the rise of pre-tightening force. Besides，the dynamic strength values of end-anchored specimens are 3.7%&ndash;7.9% lower than those of fully-anchored specimens. (2) Affected by anchor rods and pre-tightening forces，crack development in the specimens slows down，and the position of crack initiation shifts towards both sides. An increase in the pre-tightening force and anchorage length grow brings about a decrease in the fragmentation degree of specimens，and these two factors exert a stronger influence on fully-anchored specimens than end-anchored specimens. (3) The deformation compatibility process between specimens and anchor rods includes two stages，i.e.，&ldquo;advance response&rdquo; and &ldquo;delayed response&rdquo;. The strain response of anchor rods precedes that of end-anchored specimens，whereas it lags behind that of fully-anchored specimens. (4) Under dynamic impact loads，a larger anchoring length and pre-tightening force correspond to a higher support stiffness and sensitivity of specimens and a smaller peak axial force of anchor rods. The pre-tightening force should be controlled below a value that neither diminishes the strength of surrounding rock nor exceeds the yield load of the rod body，as an excessively high pre-tightening force is inconducive to the overall impact resistance of the anchor coal body. These findings are expected to offer guidance and reference for grasping the anchoring mechanism of roadway support under dynamic impact loads and the degradation mechanism of anchored bearing structures in surrounding rock.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Junchen1，2，3，WU Yongzheng1，2，3，FU Yukai2，3，HE Sifeng2，3，SUN Zhuoyue2，3，ZHOU Penghe2，3 ]]></author>
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<title><![CDATA[Study on the characteristics of AE and charge induction signal during different dip angles fault stick-slip process with fault slip rockburst]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43644.shtml]]></link>
<description><![CDATA[Fault stick slip instability can easily induce fault slip rockburst. In order to further explore the stick-slip evolution characteristics of faults with different dip angles，bidirectional friction tests were carried out on syenitegranite with faults with different prefabricated dip angles. The accumulated energy and spectral characteristics of acoustic emission and charge induction signals during fault stick-slip were analyzed，the AE sources were located，and the nonlinear characteristics of AE and charge induction time series were studied based on multifractal theory. Three quantitative indexes (maximum multi-fractal dimension Dqmax，spectral width &Delta;? and multi-fractal parameter &Delta;f(?)) with good correlation with stick slip instability were constructed，and the following conclusions were drawn：(1) With the increase of fault dip angle，the fault failure mode changes from sliding failure along the plane to sliding failure through the plane，which increases the intensity and energy of AE and charge induction signals. (2) The maximum multi-fractal dimension Dqmax and spectral width &Delta;? of the AE and charge induction signals gradually increase with the increase of fault dip angle. The maximum multifractal dimension and spectral width of the AE and charge induction signals can reflect the difference of energy released when the fault stick slip instability or severely damaged. The multi-fractal parameters &Delta;f(?) of AE and charge induction signals are all less than 0 when the fault is instability or severely damaged.，and the critical value of &Delta;f(?) can be used as the prediction index of fault stick slip instability and severe failure. (3) The dominant frequencies of the AE and charge induction signals generated by the shear slip failure of 34&deg; and 45&deg; faults are lower than those generated by the 56&deg; faults. It can be considered that the dominant frequencies of the AE and charge induction signals are related to fracture scale.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHAO Yangfeng1，DING Ling1，PAN Yishan1，2，LIUYuchun1，3，GONG Zheng1]]></author>
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<title><![CDATA[Study on progressive failure characteristics and crack propagation mechanism of double-flawed sandstone under impact load]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43641.shtml]]></link>
<description><![CDATA[In order to study the dynamic progressive failure characteristics and crack propagation mechanisms of pre-fabricated flaw sandstone，impact compression tests were conducted on sandstone specimens with pre-fabricated double flaws using the SHPB device. Real-time monitoring of crack propagation and dynamic failure processes was carried out using DIC technology，an analysis of the strength characteristics and failure modes under different flaw angles was performed to reveal the corresponding crack strain evolution mechanisms. The results show that：(1) The crack initiation load，determined by capturing the surface crack whitening，ranges between 70% and 83% of the peak load，with both peak and initiation loads exhibiting a&ldquo;U&rdquo;-shaped trend，first decreasing and then increasing with increasing flaw angle. (2) The energy dissipation rate，determined by the number of fragments，shows a significant positive correlation with the degree of fragmentation. The lowest and highest energy dissipation rates are observed for the 45&deg; and 90&deg; specimens，respectively. (3) During crack propagation，tensile cracks typically form before shear cracks，with the former distributed along the direction of the applied load and the latter appearing within an angular range of approximately 50&deg; to 130&deg; relative to the load direction. Specimens with different flaw angles exhibit three primary failure modes：&ldquo;一&rdquo;-shaped tensile splitting failure，&ldquo;X&rdquo;-shaped tensile-shear mixed failure，and&ldquo;spindle&rdquo;and&ldquo;X&rdquo;-shaped composite failure，involving six distinct crack aggregation forms. (4) The progressive failure process under impact loading is divided into three stages: elastic deformation，yield deformation，and macroscopic failure. The failure process is primarily determined by the strain concentration factor at the crack tip and the crack initiation time. The slope mean square index (K) of the curve provides a theoretical basis for evaluating the dynamic damage rate of fractured rock masses.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Qinghai1，2，XU Xiaoliang1，3*，LI Jianlin1，WU Lihua2，WANG Xiaoping1，SHI Quan1]]></author>
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<title><![CDATA[Effect of normal stress dynamic perturbation on frictional properties of simulated granite gouges and implications for fault reactivation mechanism]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43640.shtml]]></link>
<description><![CDATA[Frictional properties of fault gouges play a key role in understanding fault instability. However，the effect of dynamic normal stress perturbation(caused by tectonic movements or geological engineering) on granite fault gouges remains unclear. This paper documents 20 direct shear experiments on simulated granite gouges (grain size ＜0.25 mm) collected from Heyuan fault zone，China，to investigate frictional properties under dynamic normal stresses. All experiments were conducted，using a conventional direct shear equipment，at room temperature with a fixed shear rate of 1?m/s. Dynamic loading was applied by using square and triangular waves (initial normal stress of 10MPa，amplitudes of 1～9.5 MPa and frequencies of 0.003 3～0.001 0 Hz). Our results show：a) shear stress exhibited a clear hysteresis effect with dynamic normal stress loading；b) the apparent friction coefficient linearly decreases from 0.63 to 0.14 with increasing amplitude during loading and increases linearly from 0.63 to 0.91 during unloading. Microstructure analysis revealed that samples subjected to higher stress perturbation amplitudes were more intact and exhibited fewer tensile fracture zones. These hysteresis effects and the evolution of the apparent frictional coefficient align with the micromechanical model of grain contact proposed by Wang and Scholz. Additionally，a relationship between the apparent friction coefficient of fault gouge and the amplitude of normal stress perturbations was established based on experimental results. Using the Heyuan fault zone as a case study，we analyze the impact of dynamic perturbation in principal stress and pore water pressure on fault stability based on the Coulomb strength theory. It was found that increasing the disturbance amplitude of the maximum principal stress by 1 MPa reduces the fault shear strength by 0.18 MPa. This could reactivate faults，potentially causing seismic events with magnitude above 6 if the fault exceeds 10 km.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHU Minjie1，SHAO Kang1，LIU Jinfeng1，2，3]]></author>
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<title><![CDATA[Experimental study on engineering characteristics of foamed lightweight soil based on saline soil]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43639.shtml]]></link>
<description><![CDATA[Saline soil is widely distributed in Xinjiang area，where using saline soil as foamed lightweight soil in subgrade backfill can effectively utilize excavated waste soil，and improve the durability of subgrade in Xinjiang cold and dry area due to the good thermal insulation performance. From this perspective，the influence of density，soil content and water to dry-material ratio on engineering characteristics of saline soil-based foam lightweight soil was studied in this paper. Firstly，a series of tests were conducted to compare the thermal conductivity，fluidity，water absorption and stability of different ratios. Secondly，the unconfined compressive strength of samples under various conditions(e.g.，freeze-thaw cycle and dry-wet cycle) was obtained，in which the mechanical properties index and energy absorption rate were also studied. Finally，the pore microstructure of foamed lightweight soil was deeply analyzed by SEM and image processing software. The experimental results show that moisture and foam content greatly affect the fluidity of foamed lightweight soil. The water absorption decreases gradually with the increase in density. The foamed lightweight soil presents good thermal insulation performance. In detail，the thermal conductivity is about 1/6‐1/10 of the ordinary compacted soil. Also，there is a well-linear relationship between the density and the thermal conductivity. Under the freeze-thaw cycles，dry-wet cycles and immersed water conditions，the unconfined compressive strength of the samples decreases by 40%‐50%. Regarding microstructure characteristics，the number and roundness of pores increased with the increase in density. The structure of pores can serve as a&ldquo;bridge&rdquo;to establish a connection between its microstructure and macroscopic mechanical properties. In the study，it is recommended that the density of 800‐1 200 kg/m3，the salt soil content is not more than 40%，and the water-material ratio is 0.45‐0.55 can be regarded as the optimum ratio. The unconfined compressive strength of the described above ratio is about 0.6‐1.0 MPa，meeting the requirement of subgrade strength，thermal insulation，and durability.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LU Zheng1，2，ZHANG Rong1，3，ZHAO Yang1，QIN Lang4，LIU Jie5，YAN Tingzhou6，LI Jian6，LI Bingwei7，ZHANG Jing8]]></author>
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<title><![CDATA[Research on the radial stress gradient effect of rockburst characteristics in tunnel under true triaxial condition with single-side unloading]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43532.shtml]]></link>
<description><![CDATA[This research investigates the influence of radial stress gradient on the responses of multivariate catastrophic information of catastrophe process，fragment ejection，acoustic emission signals，and energy evolution related to rockburst in tunnel by using the self-designed rockburst test method and stress path. The three-dimensional polycrystalline discrete element numerical analyses are performed to explore the whole process of rockburst with multi-physics response，and to discuss the influence mechanism of radial stress gradient on rockburst. The findings reveal that rock samples exhibit varying degrees of rockburst under radial stress gradient of 20，50，and 80 kPa/mm. The formation mechanism of rockburst can be delineated into three progressive processes：tensile failure，shear failure，and tensile-shear composite failure. As the radial stress gradient increases，both the distribution range and number of RA-AF values of rock samples gradually increase，along with an increase in the distribution range and number of shear cracks. The rockburst fragments primarily consists of coarse，medium，and fine fragments，and macroscopic characteristics of these fragments reflect the degree of rock fragmentation. The fragmentation degree of rockburst fragments escalates with increasing radial stress gradient. The multivariate catastrophic information under varying radial stress gradients follows the hierarchy：total energy conversion rate＞elastic strain energy conversion rate＞dissipation energy conversion rate. A higher conversion rate of elastic strain energy and a lower conversion rate of dissipative energy correspond to a higher intensity level of rockburst. Furthermore，a competitive evolution mechanism between elastic strain energy and dissipation energy is evident throughout the energy evolution process of rockburst. The whole evolution process of rockburst is effectively reproduced through numerical analysis，which also captures its multi-zonal failure characteristics. Based on the observed characteristics，rockburst can be divided into two types：rupture-stripping and burst-ejection.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[SUN Feiyue1，GUO Jiaqi2，ZHANG Xiaobing1，HE Benguo3，TIAN Yongchao2]]></author>
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<title><![CDATA[Study on the deterioration law of microbial improved granite residual soil under dry-wet cycle]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43496.shtml]]></link>
<description><![CDATA[The application of Microbially Induced Calcite Precipitation (MICP) technology to improve geomaterials has become a significant research focus. However，studies on the resistance of treated soils to wet-dry cycles and the analysis of their deterioration mechanisms are still limited. Therefore，this study focuses on granite residual soil treated with microbial improvement and designs wet-dry cycle tests under typical environmental conditions. Comprehensive mechanical tests and microstructural analysis were conducted to systematically analyze the changes in mechanical properties and deterioration mechanisms of the microbially improved granite residual soil under wet-dry cycling. The results indicate that：(1) Under the influence of wet-dry cycles，the compressive strength and shear strength of the treated soil exhibit a deterioration trend that is initially rapid but gradually slows down. After 30 cycles，the compressive strength，cohesion，and internal friction angle decrease by 56.73%，38.73%，and 24.66%，respectively. The deterioration is faster during the first 12 cycles，while it significantly slows and stabilizes thereafter；(2) The porosity，density，and P-wave velocity of the treated soil exhibit a change pattern consistent with the mechanical parameters due to the dissolution of calcium carbonate cement and feldspar minerals under wet-dry cycles；(3) Microstructural analysis reveals significant improvements in the pore structure of the treated granite residual soil，with increased compaction and a marked reduction in interconnected pores. During wet-dry cycles，the dissolution of calcium carbonate cement and feldspar minerals in some interconnected pores leads to a slight increase in porosity. However，the calcium carbonate within enclosed pores remains intact，and the kaolinite produced from feldspar dissolution reacts with calcium ions to form aluminosilicate precipitates that fill and block pore channels. Consequently，the microstructural changes and the deterioration of the physical and mechanical properties of the treated soil under wet-dry cycling tend to stabilize. These research findings and insights provide valuable references for the application of MICP technology in improving granite residual soils.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHU Wenxi1，2，DENG Huafeng1，2，LI Jianlin1，2，MA Linjian3，LI Jinrui1，2，CHEN Yongqi1，2，CHEN Xiangyang1，2]]></author>
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<title><![CDATA[Study on the microstructure characteristic and its influence on strength properties of granite specimens after high temperature treatment]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43495.shtml]]></link>
<description><![CDATA[The physical and mechanical properties of rocks under high temperature conditions are the important parameters of geothermal exploitation of deep dry hot rock(DHR). To reveal the microstructure characteristic and its influence on strength properties of granite specimens after high temperature，the micro crack density，pore composition and grain size distribution were analyzed by using CT scanning，mercury intrusion porosimetry and thin section. Uniaxial compression and Brazilian splitting tests of granite after high temperature were carried out，and the evolution laws of uniaxial compression strength(UCS)，elastic modulus，Brazilian tensile strength(BTS) and UCS/BTS ratio of granite specimens were explored. The experimental results show that：(1) As the temperature increases，the UCS，elastic modulus，and BTS of granite specimens decrease，while the UCS/BTS ratio first increases and then decreases. (2) Microcracks in the thermally-treated granite specimen shift from scattered to intersecting and penetrating，and the opening and connectivity of the cracks increase with the increase of temperature. Furthermore，the microcrack area and density increase，and the smaller pores gradually transform into larger pores. (3) Intergranular cracks firstly appear in granite under high temperature，and the number of intergranular and transgranular cracks increases with increasing temperature. Moreover，the grain size increases，and internal friction angle first increases and then decreases，which is the reason for the evolution of UCS/BTS ratio of thermally-treated granite. The conclusions help to reveal the degradation mechanism of rock induced by high temperature and provide reference for geothermal exploitation of deep DHR.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HUANG Yanhua1，2，ZHANG Kunbo1，YANG Shengqi1，2，3，4，TIAN Wenling1，2，ZHU Zhennan1，2，YIN Hao1，LI Mingxu1]]></author>
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<title><![CDATA[Study on p-y curve characteristics of pile group soil dynamic interaction in overlaying water liquefied sites]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43494.shtml]]></link>
<description><![CDATA[Site liquefaction induced by significant seismic events constitutes a critical factor contributing to the structural damage observed in pile-supported bridge systems. Existing literature predominantly addresses typical sites that lack overlying water，thereby neglecting the implications of such water on pile-soil interaction dynamics. This investigation employs a centrifugal shaking table test，supplemented by numerical modeling，to elucidate the dynamic interaction characteristics between piles and soil within overlying water-liquefied contexts，utilizing p-y curves for analytical characterization. The results indicate that：(1) under substantial seismic loading，the soil stiffness surrounding piles in water-covered sites exhibits an increase，thereby demonstrating a degree of resilience to liquefaction；(2) the liquefaction processes in sites，regardless of the presence of overlying water，exhibit comparable characteristics，with the soil stiffness around piles initially diminishing before ultimately recovering；however，recovery in soil stiffness within water-covered liquefied sites occurs at a nominally slower rate subsequent to the stabilization of the excess pore pressure ratio；(3) an increase in overlying water depth corresponds to an elevation in the initial stiffness of the soil matrix while concurrently reducing the enclosed area of the hysteresis loop of the p-y curve，which adversely affects the dissipation of vibrational energy；(4) at lower amplitudes of input vibration，the presence of overlying water reduces the stiffness of the soil surrounding the pile，thereby amplifying the excess pore pressure ratio；conversely，at higher vibration amplitudes，overlying water increases the soil stiffness around the pile and diminishes the excess pore pressure ratio. The findings of this study provide crucial theoretical insights for the comprehensive evaluation of pile-soil dynamic interaction mechanisms in bridges situated within water-influenced liquefaction zones.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LAN Tian1，LI Yurun1，YAN Zhixiao1，WANG Yongzhi2]]></author>
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<title><![CDATA[Experimental study on bearing capacity of spray anchor combination support based on total safety factor method#br#]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43374.shtml]]></link>
<description><![CDATA[In order to validate the calculation model and safety factor calculation method for the combined spray-anchor support in the total safety factor method，this paper developed a large-scale tunnel structure model test system from the perspective of structural test，and carried out the loading test of the spray-anchor combined support structure under the unsupported tunnels and the different anchor spacing. The triaxial test of surrounding rock and fine sand material，and the tensile and pull-out test of anchor material were used to clarify the physical and mechanical parameters of each material in the model test，simulate the whole process of loading and damage of the spray-anchor combination support under different anchor spacing and unsupported tunnels，and monitor the stress and strain of the surrounding rock，anchor strain，inner and outer strain of the spray layer，and the displacement of the spray layer with the external load. Based on this，the design bearing capacity，ultimate bearing capacity，and deformation force characteristics of the unsupported tunnels and the combined spray-anchor support with different anchor spacing were analyzed and compared with the theoretical calculation results of the total safety factor method. The results show that：sprayed concrete and anchor can effectively carry the surrounding rock，improve the lateral limiting force of the surrounding rock，play the supporting role of the anchor rock bearing arch，and improve the deformation and bearing capacity of the surrounding rock；the bearing capacity and damage characteristics of the spray-anchor combination support obtained from the test are more in line with the results of theoretical calculations，which shows that the total safety factor method of spray-anchor combination support calculation method is reasonable and the method is on the safe side.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XIAO Mingqing1，2，XU Chen1，2，CUI Lan3，4，SHENG Qian3，4，CHEN Jian3，4，XIE Biting1，2，WU Peng3，4]]></author>
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<title><![CDATA[Study on deformation and structural mechanics characteristics of intersection section in high stress ground squeezing surrounding rock tunnels]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43352.shtml]]></link>
<description><![CDATA[To explore the asymmetric deformation characteristics and structural damage patterns in tunnel intersections，this study proposes rational intersection design configurations and suitable support systems under significant squeezing-induced deformation. Taking the Yulong Snow Mountain Tunnel of the Lijiang-Shangri-La Railway as the background，the structural deformation and biased pressure characteristics of the intersection sections were investigated based on field monitoring. Then，the influence range of the intersection and the impact of rational intersection configurations on tunnel support effectiveness were analyzed through numerical simulations. The results show that the support structures in the intersection sections exhibit significant asymmetric deformation and bias pressure characteristics under the action of squeezing surrounding rock，with support failures frequently occurring at the arch shoulders and waists. When a parallel guide tunnel intersects the main tunnel at 45&deg;and is subsequently further excavated，stress concentration is observed on both the acute and obtuse sides of the main tunnel?s support，with the acute side experiencing higher stress levels and less deformation，indicating a severe structural bias pressure. The direction of structural bias pressure on the acute side of the main tunnel is related to the distance from the intersection，with a reversal in bias pressure direction occurring between distances of 0.98D and 1.26D. Compared to 45&deg;skewed intersections，&ldquo;h-shaped&rdquo;intersections prove more effective in distributing the main tunnel?s axial stress，circumferential stress，and deformation.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HU Hui，TIAN Haosheng，YANG Wenbo，DONG Muye，ZHOU Yang，YOU Zhugang]]></author>
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<title><![CDATA[Field test of anchorage performance of BFRP anti-floating anchor under multiple cyclic loads]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43348.shtml]]></link>
<description><![CDATA[Basalt Fiber Reinforced Polymer(BFRP) anchor rods are favored for their high tensile strength and excellent corrosion resistance，making them a viable alternative to traditional steel reinforcement rods for addressing durability concerns of anti-floating anchor rods in corrosive environments. This study aimed to investigate the load-bearing performance of fully threaded BFRP anchor rods with different anchorage lengths and diameters using cyclic loading. The results show that，the anchor rod body and anchoring system display hysteresis in the stress-strain curves under cyclic loading. The anchor rod displacement exhibits high resilience upon unloading，indicating the elastic behavior of BFRP anti-floating anchor rods. The anchor rod body undergoes damage due to cyclic loading，with the strain of the rod body increasing with the number of cycles for the same anchorage depth. In anchor rods with varying anchorage depths，the strain of the anchor rod body and the plastic deformation generated after each load-unload cycle progressively increase with the number of cycles，and the strain of the anchor rod body is transferred to the deeper part of the anchor body. The axial force of BFRP anti-floating anchors' rods decreases from the top to the bottom of the borehole，and the range of the rods' axial force is in the range of 2.5 m down from the mouth of the borehole. Increasing the number of cycles results in higher axial force and deeper transmission depth of the anchor rod. However，the axial force decrease value of the anchor rod body in the range of 0.5～1.0 m from the hole opening decreases gradually with the increase of the number of cycles. The variation in axial stress of the anchor rod body is significantly influenced by cyclic loading，with peak values observed under different numbers of cycles. The shear stress of the BFRP anti-floating anchor rod rapidly increases with the increase in anchorage depth，reaching a peak value at a depth of 0.75 meters below the hole opening and gradually decreasing thereafter. The peak shear stress shows a decreasing trend with an increase in the number of cycles.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WU Zekun1，BAI Xiaoyu1，SUN Gan1，WANG Fengjiao1，YAN Nan1，DONG Xuguang2]]></author>
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<title><![CDATA[Analysis on mining-induced stress evolution and surrounding rock failure mode of roadway during heading-mining period based on continuous measurement]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43347.shtml]]></link>
<description><![CDATA[Mining-induced stress is one of the fundamental driving force of geological disasters in coal mining. In order to master the evolution law of mining-induced stress of surrounding rock during heading and mining period，in this study，hollow inclusion stress measurement technology was employed to obtain the full-cycle stress evolution data of the auxiliary roadway in the Caojiatan 122110 working face from the heading to the end of mining for the first time in China. The dynamic change law of the mining-induced stress in the surrounding rock under the influence of heading and mining was discussed，and the validity of the measured data was determined based on the M-C criterion，and the failure mode of the roadway surrounding rock was discussed using the stress ratio K. The research results show that the influence range of advance mining-induced stress during heading period and mining period was 8 m and 110 m，respectively，and the difference between maximum and minimum principal stress increases 0.17 times and 1.58 times，respectively. The increase value during mining period was 9.3 times of that during heading period. The failure mode of surrounding rock was mainly tensile failure of surface surrounding rock during period，and plastic failure occurred in a large range during mining period，in which the shallow surrounding rock is mainly tensile failure，the middle surrounding rock is tension-shear composite failure，and the deep area is generally less failure. The comprehensive field-measured data，drilling results，and in-situ failure characteristics indicate that the stress ratio K can better reflect the relationship between the stress state and the surrounding rock failure mode of the mining roadway.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[SU Chao1，2，3，KANG Hongpu2，3，JIANG Pengfei2，3，LIU Chang2，3，LIU Yuedong2，3，YI Kang1]]></author>
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<title><![CDATA[Study on the fabric characteristics and evolution mechanism of the mechanical behavior of weakly cemented Xiyu conglomerate]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43346.shtml]]></link>
<description><![CDATA[The weakly cemented Xiyu conglomerates are widely distributed in the northern and southern foothills of Tianshan Mountains in Xinjiang. The material composition of Xiyu conglomerates is complex，and their mechanical properties are poor. In order to scientifically understand the evolution laws of mechanical properties of weakly cemented Xiyu conglomerate，its grain fabric characteristics and macro mechanical properties were systematically studied by means of laboratory test and in-situ large-scale true triaxial test. The results indicate that：(1) The material composition of weakly cemented Xiyu conglomerate is relatively high in the three particle groups of gravel，coarse gravel，and medium gravel. Moreover，the particle size distribution is poor，and the contact relationships between large and coarse particles such as crushed stones and gravels show structural characteristics of particle suspension and particle support. The cementation type between particles is mainly porous cementation. (2) Affected by the characteristics of particle arrangement，weakly cemented Xiyu conglomerates exhibit obvious anisotropic deformation characteristics. The deformation modulus in the vertical direction is the largest，the deformation modulus in the long axis direction(Nearly perpendicular to Tianshan Mountain) is the smallest，and the deformation modulus in the middle axis direction(Nearly parallel to Tianshan Mountain) is in the middle. However，with the increase of stress level，the weakly cemented Xiyu conglomerates tend to become isotropic. (3) Under triaxial stress conditions，weakly cemented Xiyu conglomerate shows strain hardening characteristics during the yield stage，and shows typical plastic flow characteristics after reaching peak strength. (4) The shear strength characteristics of weakly cemented Xiyu conglomerates have obvious nonlinear characteristics，loading and unloading stress path effects and intermediate principal stress effects. The higher the stress level，the smaller the internal friction angle and the greater the cohesion. Under unloading conditions，the internal friction angle of the Xiyu conglomerate is higher than that under loading conditions，while the cohesion under unloading conditions is lower than that under loading conditions. Under true triaxial loading，the peak strength of weakly cemented Xiyu conglomerate increases with the increase of intermediate principal stress，and the influence of the intermediate principal stress on the shear strength parameter，cohesion，is more obvious. (5) The weakly cemented Xiyu conglomerate under triaxial stress states are mainly subjected to compressive-shear failure，resulting in the formation of steeply inclined main fracture zones that are connected by tensile cracks.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[FAN Lei，HU Wei，ZHANG Yihu]]></author>
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<title><![CDATA[Study on the degradation mechanism of sandstone joints in the hydro-fluctuation zone of the dry-hot valley bank slope]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43304.shtml]]></link>
<description><![CDATA[Since the Wudongde reservoir area is located in the dry-hot valley area，under the condition of periodic fluctuation of reservoir water level，the rock mass in the hydro-fluctuation zone is in the heat and wet cycle state.&nbsp; In order to study the damage evolution mechanism of sandstone joints under the action of the heat and wet cycle，the heat and wet cycles and repeated shear tests were designed and conducted on sandstone joints to analyze the shear resistance，the joint surface morphology characteristics，and the evolution law of energy parameters. The research results indicate that：(1) within 12 heat and wet cycles，the shear mechanical parameters and dimensional morphology parameters of sandstone joint surfaces show a degradation pattern of first rapid decrease and then slow stabilization. Among them，the degradation amplitude of each parameter in the first 3 cycles is significantly larger，and then the degradation trend gradually slows down，and tends to stabilize after 8 cycles. (2) As the heat and wet cycle increases，the total energy and dissipated energy of sandstone joints gradually decrease during the shear process，and their changing trend is consistent with the mechanical parameters. In comparison，the change in elastic energy is relatively small，and the trend in dissipated energy is obvious. (3) The shear performance damage mechanism of sandstone joints under the heat and wet cycle includes three aspects. Firstly，the damage effect of the heat and wet cycle on rock wall strength and joint surface morphology. Secondly，the change of joint surface morphology caused by repeated shear and the damage effect of rock mass within a certain depth range of rock wall. Thirdly，the mutual promotion effect of the heat and wet cycle and repeated shear sequence on joint surface damage. The relevant methods and results can provide a good reference for the heat and wet cycle damage degradation analysis of rock joints in the dry-hot hydro-fluctuation zone of the reservoir bank slope.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[DENG Huafeng1，XIAO Yao1，LI Jianlin1，WANG Wendong1，ZHANG Jingyu1，WAN Liangpeng2，WANG Tuanle3]]></author>
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<title><![CDATA[Numerical simulation of unloading creep and deterioration mechanism of water-bearing mudstone]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43273.shtml]]></link>
<description><![CDATA[In order to reveal the unloading creep failure mechanism of water-bearing mudstone，the rising axial pressure-reducing confining pressure creep tests，meso-structure tests and numerical simulation analysis were carried out for mudstone with different water contents. The results show that：(1) The water content has a significant effect on the creep deformation of mudstone，and the axial strain is significantly more affected by the water content than laterally at the same creep stress level. (2) SEM image analysis shows that the increase of moisture content leads to the increase of internal porosity of mudstone，and the mineral particles are dissolved and weakened，which is transformed from a dense and high strength to a loose porous and irregular accumulation structure with low strength. (3) Based on the real meso-structure characteristics of mudstone，a statistically equivalent meso-structure network is generated，and the corresponding GBM-PSC numerical model is established and verified. (4) The numerical simulation results show that the number of microcracks increases with the increase of moisture content，and the number of intragranular tensile cracks increases first and then stabilizes and then increases，while the number of intergranular shear cracks continues to increase with the increase of moisture content. The contact tangential force，angular deflection value and average porosity decrease first and then stabilize and then increase with the increase of unloading creep time，and the more the moisture content increases，the more significant the trend. (5) A three-stage unloading creep deterioration evolution model of dry and water-bearing mudstone is established，and the research results can provide a theoretical reference for the study of the creep deformation failure mechanism of excavation and unloading of soft rock engineering under the action of water.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Yu1，2，3，XIA Houlei1，2，DENG Huafeng1，2，LI Jianling1，2]]></author>
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<title><![CDATA[Calculation and model test verification of outburst prevention rock plate of tunnel in water-rich fault fracture zone]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43272.shtml]]></link>
<description><![CDATA[There are issues with the present tunnel outburst preventive rock plate thickness calculation method and the water-rich fault fracture zone mechanical model，such as incomplete factors and significant calculation error. Based on Janssen?s theory，parameters such as the horizontal angle between tunnel axis and fault fracture zone surface，fault dip Angle and groundwater depth are introduced. The correction calculation formula for the outburst prevention rock plate thickness of the tunnel crossing the water-rich fault fracture zone is derived and verified by model test. On this basis，the influences of fracture zone distribution，fault fracture zone dip Angle，water pressure and other factors on the rock plate thickness of tunnel are revealed. The results show that the calculation formula of the outburst prevention rock plate thickness has good applicability under the two conditions including fault fracture zone is inward/outward compared with rock plate for outburst prevention. Meanwhile，the thickness of tunnel outburst prevention rock plate increases with the increase of fault fracture zone distribution，water pressure，tunnel section and buried depth，and decreases with the increase of fault fracture zone inclination，the strength of ordinary surrounding rock and the intersection Angle between tunnel axis and fault fracture zone. The research results can provide theoretical reference for the safety calculation of similar tunnel engineering.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHONG Zuliang1，SHEN Zhuo1，LI Yapeng1，QIAO Hongyan2，TANG Tenglong1]]></author>
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<title><![CDATA[Model test study on the negative skin friction of pile in unconsolidated soft soil with different initial consolidation degrees]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43271.shtml]]></link>
<description><![CDATA[The primary consolidation of unconsolidated soft soil has not yet completed，hence it is sensitive to producing excessive settlement，causing drag force along pile shaft installed in these soil layers. Few discussions on the bearing capacity of piles (i.e. negative friction resistance) in underconsolidated soil have been reported，including the influence of underconsolidation degree. This paper defines a parameter termed the initial consolidation degree， ，to characterize the underconsolidation degree，and carried out three model tests under different initial consolidation degrees，in which the surcharge preloading was considered. The behaviors of negative friction resistance of pile under different initial consolidation degrees and surcharge levels were analyzed，and the coefficient of negative friction resistance and neutral point depth were discussed. The results show that the initial consolidation degree has a significant effect on the negative friction resistance of pile. With the increasing of&nbsp; (i.e.，the decrease of the underconsolidation degree of soil)，the settlement of pile，settlements of soil at various depths，axial force of pile shaft and negative friction resistance of pile all indicate a decreasing trend，and their behaviors are basically similar under different loading levels.The average values of negative friction coefficient under&nbsp; = 0.25，0.5 and 0.75 are 0.545，0.351 and 0.147，correspondingly. Comparing to&nbsp; = 0.25，the negative friction coefficients under&nbsp; = 0.5 and 0.75 are reduced by 35.6 % and 73.0 %，respectively. The increase of&nbsp; leads to the neutral point moving downward，but the downward rate gradually decreases. When&nbsp; = 0.25，0.5 and 0.75，the neutral point depths are 0.53，0.75 and 0.76 the pile depth，respectively. In addition，the increase of surcharge level causes the increase of negative friction coefficient and the decrease of neutral point depth slightly，but the effect is not significant in the holistic view when the initial consolidation degree is identical. The research results can provide technical reference for the analysis and design of negative friction resistance of piles in unconsolidated soft soil.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[GU Chuan1，2，3，YANG Yiting1，4，QIN Wei1，2，5，WANG Jun1，2，4，LIU Longqing1，5，YU Nan1，3]]></author>
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<title><![CDATA[Analytical solution for longitudinal response of tunnels with consideration of surrounding rock-concrete tangential interaction]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43270.shtml]]></link>
<description><![CDATA[The existence of faults in high-intensity earthquake areas has a serious impact on engineering structures and the longitudinal response of tunnel crossing faults needs to be studied further. An analytical solution for longitudinal response of tunnels crossing faults is presented. For the derivation，the tangential foundation springs are used to analyze the tangential contact effect of surrounding rock-lining and axial deformation characteristics of tunnel. Firstly，the elastic foundation beam model is used to simulate the surrounding rock-tunnel structure interaction. Wherein，the displacement of free field is applied on the distal end of normal foundation spring and the tangential interaction is transformed into tangential foundation springs. The analytical solution of the tunnel?s response is gotten based on the model by using Green?s function. Secondly，the numerical solution from finite difference model of 3D is used to verify the validity of the proposed analytical solutions. The results show that the tangential contact effect of surrounding rock-lining has a significant impact on the longitudinal response of tunnel. Ignoring it，the peak bending moment error of structure reaches 35.33%. Finally，the effects of fault zone width，fault elastic modulus and lining concrete grade on the longitudinal response of tunnel are explored. As the fault zone width increases，the internal force of the tunnel structure decreases；increasing the lining concrete grade results in unfavorable effect on the structure；the increase in the elastic modulus of the surrounding rock in fault zone reduces the bending moment and shear force of structure，and increases the axial force，respectively. The research results can provide a theoretical basis for the anti-offset design of tunnels crossing faults.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[CHANG Mingyu1，2，SHEN Yusheng1，2，ZHANG Xi1，2，WU Qingzi1，2，WANG Yanyan1，2，HUANG Haifeng1，2]]></author>
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<title><![CDATA[Experimental study on water-heat-salt migration and deformation characteristics of sulfate saline soil under rainfall]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43269.shtml]]></link>
<description><![CDATA[To clarify the water-heat-salt migration and deformation characteristics of sulfate saline soil under rainfall，based on the climate characteristics and saline soil types of the Hexi region in Gansu Province，a geometric similarity ratio model(1∶6) of the natural site of sodium sulfate saline soil was made in the self-developed indoor baseplate-atmospheric dual-temperature control model box. Combined with the surface energy budget balance characteristics for the first time，this natural site model was used to study the multi-physical fields coupled changes within the sodium sulfate saline soil under two test conditions of no rainfall and rainfall. The results show that rainfall can lead to a decrease in reflected shortwave radiation，downward longwave radiation，and surface temperature，an increase in surface net radiation and surface evaporation rate，and the increasing trend is related to rainfall. The rainfall leads to an increase in soil water content and conductivity，as well as a decrease in soil heat flux and temperature. Meanwhile，the rainfall leads to an increase in the heat release time of sulfate saline soil. In addition，the influence of rainfall on the water-heat-salt physical fields within the sulfate saline soil gradually weakens with increasing depth. During the transition of four seasons throughout the year，the sulfate saline soil undergoes a deformation process of first thawing settlement and then salt frost heave. Moreover，under the influence of rainfall，the thawing settlement deformation and salt frost heave deformation of sulfate saline soil show varying degrees of increase. The research results provide certain guidance for addressing environmental disasters and engineering issues in salted regions under the background of climate change.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHOU Zhixiong1，ZHOU Fengxi1，ZHANG Mingli1，MA Qiang2]]></author>
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<title><![CDATA[Development and application of bidirectional dynamic cyclic shear test system for rock joints]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43268.shtml]]></link>
<description><![CDATA[To deeply explore the shear mechanical behavior and failure mechanism of rock in a complex engineering environment，the bidirectional dynamic rock shearing test system was independently designed and developed. The test system is mainly composed of five parts：host loading system，servo oil source system，shear tooling system，and deformation measurement system. The main innovations of the test system are as follows：(1) Dynamic loading can be carried out in the normal and shear directions at a frequency of 0.001 ~ 10 Hz，and the mixed loading and unloading control of tangential displacement，tangential load，normal displacement and normal load can be realized simultaneously. The normal center of the sample can be kept constant by the method of bidirectional shear. (2) We can use load，cylinder displacement，and deformation sensors for multi-rate and multi-objective combination control to achieve tangential and normal dynamic and static loading in the test process；(3) Multiple controllable boundary conditions such as constant stress，constant displacement，constant stiffness，dynamic loading and customized load forms can be realized；(4) Large-size specimens with L&times;W&times;H = 200 mm&times;100 mm&times;100 mm or 400 mm&times;200 mm&times;200 mm can be researched；(5) The coupling mechanism under various working conditions such as shearing and anchoring can be explored simultaneously. The reliability and accuracy of the test system were verified by carrying out rock shear tests under different stress boundary conditions with this test system. The test results show that the developed bidirectional rock joints dynamic shear test system can meet the scientific research needs of rock shear mechanical behavior. The system is easy to operate and the test process is efficient and stable. The loading accuracy and test data accuracy are high. The test system can provide an important platform for research in major engineering fields such as deep coal resource mining，roadway (tunnel) excavation and construction，radioactive nuclear waste disposal，slope stability analysis in earthquake zones and underground energy storage.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Qiang1，2，GU Qiuxin1，2，LI Tao1，2，LIU Richeng1，2，LI Shuchen1，2，YIN Qian1，2，XU Dingping3]]></author>
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<title><![CDATA[Experimental study on deformation，permeability and AE characteristics of sandstone under multi-stage cyclic loading with a constant amplitude]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43267.shtml]]></link>
<description><![CDATA[In order to explore the influence of multi-stage cyclic loading with a constant amplitude on rock deformation，damage and permeability，a four-stage cyclic loading and unloading triaxial test was carried out on sandstone samples under different confining pressures. The permeability was measured and acoustic emission (AE) signals were monitored in real time during the test. The effects of confining pressure and cyclic loading on the characteristic stresses，permeability，b-value and RA-AF (risetime/amplitude - average frequency) value of AE signals during multi-stage cyclic loading are analyzed. The results show that：(1) Compared with the conventional triaxial compressive test，the volume strain of the sandstone crack under each stage of the multi-stage cyclic loading test is expanded，and the peak stress decreases. With the increase of confining pressure，the difference between the two peak stresses decreases，and the cyclic loading effect is weakened. (2) Under both the conventional triaxial loading and multi-stage cyclic loading conditions，the permeability decrease first and then increase. After cyclic loading，the permeability strain-based loss rate(PSL) of the rock sample is smaller，and the macroscopic deformation of the rock is aggravated. When the confining pressure increases，the PSL increases and the macroscopic deformation decreases. Under low confining pressure，the stress-based irrecoverable permeability coefficient(EIP) in each cycle is negative or small，and the permeability increases. Under high confining pressure，EIP value in the fourth cycle is positive，and the formation of seepage channel is affected by confining pressure constraints. (3) Compared with the conventional triaxial test，the b-value of AE signals under multi-stage cyclic loading fluctuates more. Under the two loading modes，the rock samples are dominated by tensile cracks. Under the condition of multi-stage cyclic loading，there are more shear cracks in the rock sample，and with the increase of confining pressure，the proportion of rock tensile cracks gradually decreases，and the proportion of shear cracks increases.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[CHEN Xu1，2，XIAO Yi2，TANG Minggao1，2，JIAO Tong2，ZHANG Fan3]]></author>
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<title><![CDATA[A novel method for solving the location and depth of tension cracks at the rear edge of rock slopes under stress analysis mechanism]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43265.shtml]]></link>
<description><![CDATA[Tension cracks at the rear edge of a slope often have a significant impact on the stability of rock slopes，how to effectively predict the location and depth of tension cracks becomes a key prerequisite for reliable analysis of the stability of rock slopes with tension cracks. Thus，a novel method is developed to solve the location and depth of tension cracks at the rear edge of rock slopes，specifically focusing on rock slopes without joints or with four or more sets of joints，based on the formation mechanism of tension cracks. The present method begins by applying the nonlinear generalized Hoek-Brown(GHB) strength criterion，which incorporates the influence of joints into the calculation of rock mass strength. Furthermore，given the approximate vertical development of tension cracks at the rear edge of the slope，the horizontal stress state of the rock mass becomes a crucial factor in the formation and development of tension cracks. Consequently，a micro-wedge unit mechanical analysis model is introduced to determine the horizontal stresses of the rock mass at the rear edge of slope. Thereafter，based on the top-down development pattern of vertical tension cracks at the rear edge of slope and the relationship between the terminal stress level of the tension crack and the rock mass&rsquo;s tensile strength，a discriminant formula is formulated to calculating the location and depth of tension cracks at the rear edge of slope. The rationality and effectiveness of the present method is verified by comparing with the numerical simulation method，laboratory test results，and engineering measured data. The research findings provide a theoretical basis for predicting the location and depth of tension cracks at the rear edge of rock slope and establish necessary conditions for a reliable stability analysis of rock slopes with tension cracks at the rear edge.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[DENG Dongping，PENG Yihang，CHEN Haoyu]]></author>
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<title><![CDATA[Experimental study on tackifying-frost resistance of tunnel surrounding rock-spray interface in cold region]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43259.shtml]]></link>
<description><![CDATA[Tunnels in cold regions are generally affected by freeze-thaw action，which is prone to damage and debonding along the interface between concrete lining structure and surrounding rock，which seriously affects the construction quality and safe of tunnel engineering operation. In order to improve the bonding strength and frost resistance of the tunnel surrounding rock-spray layer interface，the surrounding rock-spray layer interface is simplified into a rock-concrete binary body. The cement-based interfacial agent is developed for improving the adhesion and frost resistance of the spray layer interface. A comparative test of the bonding strength and frost resistance of the sandstone-concrete interface was carried out before and after the spraying of the cement-based interface agent. The test results show that：(1) The main chain fracture parallel to the silicon-oxygen tetrahedron in the rock-concrete interface caused by freeze-thaw action is the core reason for the decrease of the bonding performance of the rock-concrete interface. (2) Through the test and development，the optimal mix ratio of cement-based interfacial agent suitable for improving the interfacial adhesion and frost resistance of tunnel spray layer in cold regions is proposed as follows∶cement∶water∶silica powder∶silane coupling agent∶polymer cementitious material(water-based acrylate peritoneal gel + bamboo liquefied phenolic resin) = 10∶4.4∶0.8∶0.2∶1∶0.5；(3) Due to the polymer hydration of the cement-based interfacial agent，the 'root pile' effect generated at the interface of the spray layer expands the degree of plugging on the contact surface between the rock and the concrete. At the same time，the chemical bonding of the silane coupling agent enhances the mechanical bite force between the interfaces. The coupling enhancement of the two improves the bond shear strength and splitting strength of the rock-concrete interface. Through comparative tests，it is found that after 30 freeze-thaw cycles，the shear strength of the rock-concrete interface can be increased by 109% compared with the untreated sample，and the bond splitting strength is increased by 78%. (4) The silicon-oxygen bond produced by the hydrolysis and condensation of siloxane in the cement-based interfacial agent is adsorbed on the hydrophobic layer formed at the rock-concrete interface，which inhibits the expansion of the interface water-rich zone；the silicon gel generated by the combined reaction releases heat by phase change，which reduces the freeze-thaw damage of the rock-concrete interface and inhibits the initiation and propagation of cracks at the rock-concrete interface. (5) The developed cement-based interfacial agent itself has good frost resistance，especially in the freeze-thaw environment of －10 ℃&ndash;10 ℃，it can effectively improve the adhesion and frost resistance of the surrounding rock-spray layer interface. This paper provides a new solution for the thickening and frost resistance treatment of tunnel surrounding rock-spray interface in cold region.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Hui1，XU Hainan1，REN Jianxi1，SHEN Yanjun2，3，JIA Hailiang1，XI Jiami1，TANG Liyun1，YU Jinjie1，WEI Yao4]]></author>
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<title><![CDATA[Analysis of macroscopic strength and meso-scale particle rotation characteristics of railroad ballasts fouled by different levels of coal dust#br#]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43258.shtml]]></link>
<description><![CDATA[Fouled ballast can commonly cause severe defects of ballasted trackbed including mud pumping and uneven settlement，thus further endangering stable and safe operations of trains. To address this engineering challenge，ballast specimens with different fouling levels were prepared in the laboratory by adopting the classic fouling index(FI)，and subsequently subjected to monotonic triaxial compression tests. The newly-invented wireless，self-powered，and smart sensors(SmartRock) were placed at different positions inside ballast specimens to measure real-time particle rotation data. The macroscopic shear strength behavior of ballast specimens with different fouling levels were analyzed comparatively and linked to meso-scale ballast particle movement. The results show that increasing coal dust fouling level could cause gradual transition of macroscopic behavior from strain hardening to strain softening. When the fouling index(FI) value ranged from 10% to 15%，both peak deviator stress at failure and apparent cohesion reached their minimums，respectively. The rotation of ballast particles inside the triaxial specimens mainly occurred in the vertical planes，whereas the vertical-plane rotations of ballast particles located closer to the bottom of clean ballast triaxial specimens increasingly attenuated due to the increasing restraint of lateral boundaries on particle movement. When the FI value reached 15%，no discernible rotation patterns were observed for ballast particles inside triaxial specimens，which may be attributable to the loss of inter-particle force-transferring skeleton. When the FI value further exceeded beyond 15%，ballast particle rotations exhibited significantly increasing differences，probably resulting in macroscopic mechanical instability. The uniformity of ballast particle rotations determines macroscopic shear strength behavior to a certain extent. Therefore，the coefficient of variation of the vertical-plane peak Euler angle of ballast particles could be potentially used as a meso-scale indicator of the actual fouling level of ballast beds. The findings are expected to provide theoretical basis and technical reference for Non-destructive evaluation of fouling degree，optimizing ballast-cleaning schedules and implementing intelligent maintenance of ballasted trackbeds.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Meng1，XIAO Yuanjie1，2，ZHANG Chongchong1，YANG Tao1，TAN Pan1，LU Mingjiao3]]></author>
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<title><![CDATA[Experimental study on the effect and weakening mechanism of water on impact-induced rockburst]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43237.shtml]]></link>
<description><![CDATA[To investigate the weakening mechanism of water on impact-induced rockburst，15 experiments were performed considering different water content levels on cubic sandstones. Photography and acoustic emission (AE) system were used to monitor the rockburst process. According to the photography results，impact-induced rockburst under different water content levels all experience three processes：particle ejection，debris peeling，and comprehensive rockburst. In addition，the results also show that the higher the water content level，the lower the intensity of the rockburst. This effect is reflected in the fact that the AE energy，the quality and the fractal dimension of fragment show a decreased trend with the increase in the water content level. Based on the perspective of energy and micro-crack evolution，two mechanisms are proposed to explain the weaking effects of water on rockburst intensity，including：(i) water increases the plastic deformation capacity，weakens the energy storing capacity and reduces the rockburst tendency of sandstone，resulting in a slightly intensity of rockburst；(ii) water accelerates the expansion of shear cracks，which is not conducive to the occurrence of plate cracking before rockburst，and destroys the conditions for rockburst inoculation.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Dongqiao1，SUN Jie1，2，CAO Binghao1，2，HE Manchao1，ZHANG Ziqian1，2，PENG Dong1，2]]></author>
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<title><![CDATA[Experimental and theoretical study on the creep behavior of Tamusu mudstone]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43236.shtml]]></link>
<description><![CDATA[This study focuses on Tamusu mudstone，an argillaceous rock from the preselected area for high-level radioactive waste(HLW) underground disposal in China. Based on the previous work on the evaluation of argillaceous rock for the HLW geological disposal repositories，a systematic experimental and theoretical study is conducted on the creep characteristics of Tamusu mudstone under complex conditions. Creep tests show a positive correlation between deviatoric stress and creep deformation under the same confining pressure. The elastic modulus shows a trend of first increasing and then decreasing during the creep process. The creep deformation of Tamusu mudstone results from the combined effect of strengthening and structural degradation. Based on the creep behavior of Tamusu mudstone，creep hardening variables and creep damage variables were introduced，and further the creep yield surface and creep potential function were constructed based on Perzyna?s overstress theory. A creep constitutive model for Tamusu mudstone was established，and it was numerically implemented and verified by the software ABAQUS and its UMAT subroutine. This study comprehensively and systematically interprets the creep deformation law and deformation mechanism of Tamusu mudstone in the HLW disposal environment，providing an important theoretical basis for the safety，feasibility，and suitability evaluation of China?s argillaceous rock HLW geological disposal repository. The research work has important practical value for the development and long-term safety of China?s nuclear industry.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YU Hongdan1，LU Chen2，CHEN Weizhong1，HUANG Jiawei1，LI Honghui3]]></author>
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<title><![CDATA[Experimental study on sand fixation characteristics of modified fly ash materials]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43235.shtml]]></link>
<description><![CDATA[粉煤灰是火力发电的主要废弃物，在中国西部地区广泛存在，受交通影响，处置成本高，西部宁夏甘肃地区沙漠化问题严重，基于两者供需关系开展粉煤灰改性材料固沙应用研究。文章基于固沙效果制定了参考固沙标准，针对改性粉煤灰固沙材料，通过单轴抗压强度试验、含水率试验、扫描电镜试验(SEM)、X射线衍射试验(XRD)、剪切试验等多种分析方法对改性粉煤灰材料的力学性质、水化产物和微观结构进行研究。结果表明，改性粉煤灰材料单轴抗压强度和胶结效果均得到了显著提高，改性粉煤灰材料水化后形成的水化硅酸钙凝胶是解释保水性差异的关键；10%碱激发剂改性粉煤灰胶结体黏聚力提升为原来的3倍以上，30%镁渣改性粉煤灰胶结体抗剪强度显著提高。文章建议采用低剂量碱激发剂(2.5%左右)或高剂量(大于30%)镁渣改性粉煤灰，并适当提高灰沙比，以获得更好的经济效益和固沙效果。]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LU Haifeng1，2，LI Zhongyang1，ZHANG Kai1]]></author>
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<title><![CDATA[Study on dynamic mechanical properties and crack extension law of water-saturated fractured sandstone]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43234.shtml]]></link>
<description><![CDATA[In order to study the dynamic mechanical properties and crack extension law of water-saturated fractured sandstone，sandstone specimens with seven prefabricated crack inclinations(0&deg;，15&deg;，30&deg;，45&deg;，60&deg;，75&deg;，and 90&deg;) were saturated with water，and impact compression tests were carried out with the SHPB test device. The results show that the dynamic stress-strain curves of prefabricated and natural sandstone samples with different inclination angles are similar，and can be roughly divided into three stages. The dynamic compressive strength，dynamic strain and dynamic elastic modulus all showed an overall trend of decreasing and then increasing with increasing fracture inclination. Compared with prefabricated natural sandstone specimens，the dynamic compressive strength and dynamic elastic modulus of the water-saturated sandstone specimens were slightly increased，while the dynamic strain was reduced，showing the Stefan effect of water action under dynamic loading conditions. With the change of fracture inclination，the failure modes of water-saturated sandstone specimens are tensile，shear and tension-shear composite failure modes. The fracture inclination is 0&deg; and 15&deg; for type II failure，30&deg;～75&deg; for I-II composite failure，and 90&deg; for type I failure. The crack initiation position of prefabricated fractured sandstone specimens is mainly concentrated near the fracture tip，and the crack initiation angle decreases with the increase of the fracture inclination angle，and the crack initiation angle at the incident end is larger than that at the transmitted end.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[PING Qi1，2，3，SUN Shijia2，3，GAO Qi2，3，WU Shiwei2，3，LI Xiangyang2，3，XU Yijie2，3，HU Jing2，3，TANG Qinglin2，3]]></author>
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<title><![CDATA[Research on classification of rock tensile-shear fracture based on acoustic emission RA-AF values and kneedle algorithm]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43233.shtml]]></link>
<description><![CDATA[The accurate determination of the boundary equation is crucial for the classification and identification of cracks in the rock fracture process using the acoustic emission RA-AF values. The granite shear acoustic emission monitoring experiment was carried out. Based on the crack classification method of acoustic emission RA-AF，the influence rule of slope k and intercept b of the boundary equation on the crack classification results was analyzed. With the help of kneedle algorithm of inflection point monitoring，a method to accurately determine the boundary equation was formed. Based on this，the results of crack classification were discussed and analyzed. The results indicate that both the slope k and the intercept b of the boundary equation have an impact on the crack classification results，and the influence depends on the size of the value of k and b. There exist critical slope ，and critical intercept . When the values are below the critical values，the classification results are greatly affected. While when they exceed the critical values，the impact on the classification results is small or almost negligible. The kneedle algorithm for inflection point detection can effectively determine the critical points of the boundary equation's slope and intercept，which provides a method and basis for accurately determining the critical slope and intercept in the boundary equation. Compared with the boundary equation without intercept，if the boundary equation has intercept b，the proportion of shear cracks will increase by about 20%. The research results provide a basis for determining the boundary equation of rock tensile-shear crack classification using acoustic emission RA and AF values，which is helpful to promote the application of this method in rock mechanics.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Juxian1，LIANG Peng1，2，ZHANG Yanbo1，2，YAO Xulong1，2，YU Guangyuan1，2，GUO Bin1，3]]></author>
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<title><![CDATA[Study on the quantitative definition of blasting damage zone scope based on wave velocity field inversion]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43231.shtml]]></link>
<description><![CDATA[Determining the scope of the rock mass blasting damage zone is important for evaluating the stability of underground engineering surrounding rock under blasting and controlling bedrock damage under excavation. A method based on wave velocity field inversion was proposed to determine the rock blasting damage zone scope quantitatively. This method was based on multistencils fast marching methods(MSFM) and simultaneous iterative reconstructive technique(SIRT). The effectiveness of the proposed method was verified by comparing the inversed wave velocity field with the known one. Blasting and wave velocity measurement simulations were carried out on the self-developed finite-discrete element solver OpenFDEM. The waveform data were processed using a self-programmed post-processing program，and thus the post-blasting wave velocity field was reconstructed. Based on the relationship between the changing rate of wave velocity and the degree of rock mass damage in the current code，the areas with different wave velocity changing rates were compared with the areas of cracks. The scopes of the blasting damage zone with different damage degrees were quantified using the ratio of the equivalent radius to the blast hole radius. 10% and 15% of the wave velocity changing rate were used as the thresholds for defining slightly and completely damage of the rock mass，respectively. The ratio of the equivalent radius of the slightly damage zone and the damage zone to the radius of the blast hole is about 11.86 and 7.2，respectively. As the blast load increases，the shape of the damage zones with different damage degree becomes irregular and the equivalent radius increases. The study results are expected to provide a reference for determining the scope of the blasting damage zone in the field.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[FU Shuaiyang1，2，LI Haibo1，2，WU Di1，2，WANG Ben1，2，LIU Liwang3，LI Xiaofeng1，2]]></author>
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<title><![CDATA[Stability analysis of unsaturated slope reinforcement with anchor plate support structure]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43228.shtml]]></link>
<description><![CDATA[To improve the design approach of anchor plate supporting slope，the calculation formula of anchor plate size is proposed according to the internal balance of slope，and the formula of safety factor of unsaturated anchor plate supporting slope is obtained through the variational method combining limit balance method. By using transient seepage to simulate rainfall conditions，the variation rule of slope safety factor with rainfall time was obtained，and the internal mechanism of slope safety factor variation was analyzed. The results of safety factor are compared with the results of existing methods by 4 examples，and the rationality of the suggested formula is verified. The effects of rainfall intensity，seismic conditions and anchor plate supporting conditions on slope stability and sliding surface are analyzed. The results show that heavy rainfall and earthquakes will significantly reduce slope stability. Horizontal and vertical seismic forces will lead to deeper sliding surface，while vertical downward seismic forces will lead to shallower sliding surface. The proposed approach can not only calculate the safety factor of saturated and unsaturated slope，but also calculate the safety factor of slope under transient seepage and steady seepage，and has strong applicability. In order to facilitate the engineering application，by comparing the slope safety factor when the anchor plates are arranged at different vertical spacing，the vertical 3m spacing arrangement of the anchor plate is given as engineering suggestion. A simple method for the size design of anchor plate is presented. The size of anchor plate obtained by the simple design approach is much lower than the existing empirical design size.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[PENG Junguo，HUANG Yuhao，SONG Ranran，ZHANG Chengzhi]]></author>
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<title><![CDATA[Study on the seepage and heat transfer effect in rough fracture with hot matrix considering the dynamic thermophysical properties of fluid]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43227.shtml]]></link>
<description><![CDATA[To study the coupling mechanism of seepage and heat transfer in high-temperature rough rock fracture and improve the efficiency of geothermal energy extraction，based on lattice Boltzmann method the double distribution functions were applied to deal with the evolution of seepage velocity field and heat transfer temperature field separately. Considering the effects of fluid temperature on its kinematic viscosity and thermal diffusion，a numerical model was proposed to simulate the coupled process of seepage and heat transfer in rough rock fracture. And the accuracy of the model was verified according to a classic example. Based on the proposed model，the effects of rough fracture surface and dynamic evolution of fluid physical parameters on the coupling mechanism of seepage and heat transfer was analyzed，and the relationship between the roughness of fracture surface and the performance indicators of geothermal extraction was discussed. The results show that the obstruction effect of the rough fracture surface increases the inertial pressure drop and reduces its seepage velocity，which makes the heat transfer between water and rock more sufficient，and the water temperature is higher at the outlet. Neglecting the influence of fluid temperature on its kinematic viscosity seriously overestimates the flow velocity，and significantly underestimates the thermal breakthrough time. As the roughness of the fracture surface intensifies，its thermal breakthrough time gradually increases，while the heat production power shows a decreasing trend. When the fractal dimension of fracture surface is 1.079 8，its thermal breakthrough time increases by 191.49% compared to the smooth fracture，and the heat production power is only 44.36% of that of smooth fracture. In addition，when the pressure drops are the same，the smoother the fracture surface is，the higher the heat recovery rate obtained within the same time. However，due to its shorter heat breakthrough time，the heat recovery rate is significantly reduced when the thermal breakthrough occurs.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[SHEN Linfang1，SU Wei 1，ZHANG Jiaming1，WANG Zhiliang1，LI Shaojun2，XU Zemin1]]></author>
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<title><![CDATA[Quantification method of pore structure in low illuminance borehole images based on pixel spatial information]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43226.shtml]]></link>
<description><![CDATA[Given the technical challenges of insufficient image clarity and inaccurate quantitative characterization in the in-situ detection of pore structures on low reflection rock walls，this paper proposes a quantification method of pore structure in low illuminance borehole images based on pixel spatial Information. By synchronously utilizing borehole wall images and point cloud data to obtain pixel spatial feature information of non-standard cylindrical borehole shapes，the quantification process of pore structure in low reflection characteristic rock layers under complex geological conditions is achieved. Firstly，based on the low illumination borehole wall image features with alternating light and dark textures that are often formed in the actual drilling environment and testing process，a borehole wall eccentricity image correction model that is suitable for the actual hole testing environment is constructed to form a cosine light and dark texture suppression function that can effectively weaken the hole wall light and dark texture phenomenon. Subsequently，a low illumination borehole wall image enhancement algorithm based on detail feature weighted fusion is proposed to enhance the texture information of low illumination borehole wall images. Finally，combining the division of pixel spatial cells and the calculation of horizontal and vertical scales of pixel spatial points，a pore structure quantification method utilizing pixel spatial information is formed. At the same time，combined with practical case analysis，the correctness and superiority of the method proposed in this paper are verified. The results show that the method can obtain pixel spatial feature information of borehole walls in non-standard cylindrical drilling shapes，which can provide a new technical method and means for in-situ detection of pore structures in low reflection characteristic rock layers under complex geological conditions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Jinchao1，HAN Zengqiang1，WANG Yiteng1，WANG Chao1，ZHANG Guohua2]]></author>
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<title><![CDATA[Shear behavior of Pile-soil interface considering ice film thickness and frost jacking calculation]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract43222.shtml]]></link>
<description><![CDATA[The shear behavior of the contact interface between frozen soil and pile is an important basis for establishing the frost jacking calculation model of pile in frozen soil regions. A series of negative temperature direct shear tests of frozen sand soil and concrete with different ice film thickness at the contact interface were carried out to analyze the influence of ice film thickness on the shear mechanical deformation characteristics of the interface. Combined with multiple regression method，a trilinear shear constitutive model with multiple factors was established. Based on the shear-displacement method，the trilinear shear constitutive model is introduced to establish a theoretical calculation model for the frost jacking behaviour of single pile during the process of unidirectional freezing of seasonal frozen soil，and an example is analyzed. The results show that the ice film thickness has a significant effect on the shear behavior of the interface，and the relationship between the peak shear strength and the residual shear strength and the ice film thickness can be approximated as hyperbolic functions. The shear constitutive model can better reflect the effects of interface temperature，normal stress and ice film thickness on the shear behavior of frozen soil-concrete interface. Some pile-soil interface will slip during the freezing process of the soil around pile，and the peak position of tangential frost heaving force moves downward with the development of frost depth. The thickness of ice film has significant influence on the frost jacking effect of pile foundation. The frost jacking force does not increase linearly with the increase of frost heaving ratio，which is mainly affected by the shear strength between pile and frozen soil.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHOU Yalong1，2，WANG Xu1，3，JIANG Daijun1，LIU Deren1，HE Fei1，HU Yuan1，LIU Ping1]]></author>
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<title><![CDATA[Typical landslide-induced wave experimental study on energy reduction and wave descent]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42734.shtml]]></link>
<description><![CDATA[A large number of reservoir-induced landslides caused disasters in the form of impulse waves in western China. If all landslides that may generate waves are prevented and controlled by current specification，the economic cost is huge. This paper taking Shuipingzi 1# landslide in Baihetan reservoir as an example to carry out application demonstration，a three-dimensional physical prototype model experiment was constructed with a geometric scale of 1∶150，and landslide energy reduction and wave descent experiments were carried out to find more economical landslide-induced impulse wave risk reduction solution. Physical test showed that under extreme conditions of the impounding water level with 825 m above sea level combined with a VIII-degree earthquake，the landslide would slide into Baihetan reservoir with the maximum speed of 7.37 m/s，and the maximum generated wave amplitude would be 7.59m. The maximum runup around Xiangbiling community was about 3.5 m above the ground，which would seriously threaten the safety of the riverway with the length of more than 4.5 km and the safety of Xiangbiling community. As the removal volume increases from 10&times;104 m3 to 47.9&times;104 m3，the effect of reducing energy and wave becomes evident. Wave making energy transmitted from landslide decreased by about 94.8%，the maximum wave amplitude and the maximum runup around the Xiangbiling decreased to 4.35 m and 1.73 m，respectively. The area with the impulse wave larger than 1 m was only distributed in the landslide course and the opposite bank of Jinsha River，and the risk of landslide-induced impulse wave decreased sharply. Based on this，this study proposes and discusses the feedback design mentality and the realization method of the safety margin of landslide-induced impulse wave risk reduction engineering design，which using the hazard degree of landslide-induce impulse wave as a measurement indicator，and recommends a risk reduction design scheme that can greatly reduce the economic cost of Shuipingzi 1 #landslide treatment. The design mentality of risk reduction prevention for landslide-induced impulse wave is a useful supplement of landslide control specification，which has yet to be further developed and promoted.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HUANG Bolin1，2，DONG Xingchen1，2，YIN Yueping3，LI Renjiang4，JIANG Shu4，LI Yang1，2，ZHANG Peng1，2，QIN Zhen1，2，YAN Guoqiang4]]></author>
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<title><![CDATA[A sample preparation method for acid-sensitive weakly-cemented artificial sandstone with its application in acid-erosion seepage test]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42726.shtml]]></link>
<description><![CDATA[Carbon storage is an effective way to reduce CO2 emissions and mitigate environmental problems such as global warming. The porosity and permeability characteristics of storage reservoir are the key factors to determine the efficiency of CO2 storage，one important mechanism among which is the weakening of calcite cementation by acid erosion，and it is therefore necessary to carry out the researches on weakly cemented sandstone sensitive to acid. This study developed a prepare method of acid-sensitive weakly cemented artificial sandstone，conducted the deformation analysis of acid-sensitive weakly cemented sandstone during acid erosion process，and investigated the change laws of sandstone permeability before and after acid erosion. Firstly，based on the response surface experimental method，the effects of different urease activity，concentration of cementing fluid and concentration of skim milk powder on the strength of acid-sensitive weakly cemented artificial sandstone were studied，and a regression model considering multiple factors was established. Secondly，the acid erosion seepage tests of acid-sensitivity weakly cemented artificial sandstone under different stresses were carried out to analyse the deformation of sandstone during acid erosion：During acid erosion，the sandstone strain increases linearly with the acid flow，and the cementation weakening induced by acid erosion seepage can make the sandstone shrinkage strain exceed 4%. Finally，the change of sandstone permeability before and after acid erosion was studied：The permeability reduced by 70% under high confining pressure. The study reveals the acid erosion characteristics of weakly cemented sandstone，which has a certain guidance on CO2 geological storage project.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YANG Xin1，HONG Yi1，2，WANG Llizhong1，2，GUO Zhen1，2，ZHENG Jianan1，YAN Mengqiu2]]></author>
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<title><![CDATA[Study on fracture characteristics and rockburst process of hard sandstone with high ground stress]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42721.shtml]]></link>
<description><![CDATA[To study the hard sandstone rockburst failure characteristics under high ground stress and simulate the &quot;damage&quot; failure characteristics of the rock mass in that state，a Mode I/II mixed cohesive zone model based on Park-Paulino-Roesler(PPR) potential energy function was established. Through disk-shaped compact tension test and punch-through shear test，the Mode I and Mode II fracture characteristics of hard sandstone were studied，and model parameters were obtained. Then，a numerical model is established to simulate the rockburst of hard sandstone tunnel under high ground stress. The stress and energy of the elements in the process of rockburst are tracked to analyze the process and failure characteristics of rockburst in hard sandstone tunnel. The research results indicate that：(1) The shear strength and Mode II fracture energy of hard sandstone increase with the increase of confining pressure. When the confining pressure exceeds 30MPa，the Mode II fracture performance tends to stabilize. (2) When the vertical stress is much greater than the horizontal stress，the hard sandstone tunnel mainly experiences tensile-toppling rockburst in the form of layered spalling or wedge-shaped burst；On the contrary，shear-bursting rockburst characterized by penetrating shear failure in rock mass will occur. When the horizontal stress and vertical stress are both large，the unloading failure mode of rock mass mostly shows the characteristics of tensile-shear composite failure，and the tensile-stripping rockburst mainly occurs.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Zhiqiang1，2，ZHANG Kangjian1，2，XU Jialei1，2，LUO Chun1，2]]></author>
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<title><![CDATA[Study on thermo-mechanical response characteristics of horizontally loaded energy pile in saturated clay]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42642.shtml]]></link>
<description><![CDATA[Currently，the research on the thermo-mechanical response of energy piles primarily focuses on vertical loads，while studies considering the influence of horizontal loads are relatively limited. To investigate the thermo-mechanical response characteristics of horizontally loaded energy piles，a model test was conducted to analyze the variations in pile top displacement，pile bending moment，pore pressure，and soil pressure in front of the pile under different temperature gradients in saturated clay. The research results showed that both heating and cooling of the pile induced additional pile top displacement，with cooling causing a larger additional displacement，reaching 0.22%D (D is the diameter of the pile)，while heating induced an additional displacement of 0.13%D. The ultimate bearing capacity of the pile increased after heating/cooling compared to the ultimate bearing capacity pile，with a greater increase observed after heating，approximately 32.7%，compared to an increase of approximately 26.1% after cooling. This was due to the significant increase in the strength of the soil caused by the thermal consolidation effect during heating. Heating and cooling did not have a significant impact on the location of the maximum bending moment，as the maximum bending moment consistently occurred at 37.5%L (L is the burial depth of the pile) before and after heating/cooling. The maximum bending moment increased after heating/cooling. During cooling，the maximum bending moment initially increased and then stabilized gradually. During heating，the maximum bending moment decreased first and then gradually increased，exceeding the pre-heating moment. Throughout heating period，the pile top displacement continued to increase，suggesting that the pile may undergo rigid rotation in the initial stage of heating. Heating and cooling have different effects on the soil pressure in front of the pile. Overall，the upper part of the soil pressure generally increased and the lower part decreased. Heating and cooling caused variations in pore pressure in the soil，resulting in positive or negative excess pore pressure.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHAO Hua1，WANG Chenglong1，2，3，CHEN Zhixiong1，ZHANG Dingxin1，PENG Chen1]]></author>
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<title><![CDATA[Experimental study on fault activation of different infiltration interface types in gas energy storage process of abandoned oil and gas reservoirs]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42641.shtml]]></link>
<description><![CDATA[Through conducting the triaxial unloading-induced slip tests of different types of rock structural planes with dry，wet and crude oil interfaces，the effect of interface types on the activation process of rock structural planes was explored，and the correlations between the microscopic characteristics and macroscopic performance of structural planes during the activation process were revealed. The results show that the activation of rock structural plane is divided into three stages，i.e.，stable stage，activation stage and dynamic slip instability stage. During shear sliding of rock structural plane，rock fragments resulting from the shearing and exfoliation of rock structural plane accumulate in the form of bedding，with greater damage observed at the edges of the structural plane compared to the interior. The JRC degradation rate of rock structural plane with dry interface is 62 % after the triaxial tests，which is greater than that of dry interface(33.6 %) and crude oil interface(30.5 %). For the structural plane with dry interface，the asperities on the structural plane are strongly self-locked，and the average slip rate is low(0.13 &mu;m/s) in the stable stage. While in the stick-slip stage，the damage of the asperities on the structural plane is primarily brittle failure with suddenness，which leads to the average slip rate of stick slip reaching 9.7 &mu;m/s，74 times larger than that in the stable stage. For the structural plan with wet interface，the presence of water promotes the occurrence of stick-slip events. During stick-slip，the damage of the asperities is mainly ductile failure，and the slip rate transition exhibits a sharp increase followed by a falling process. The mixing of rock fragment and water during shear slip increases the contact area between the adjacent structural plane，improves the intermolecular adsorption force，and strengthens the friction strength of the rock structural plane. For the structural plan with crude oil interface，a layer of colloidal crude oil is attached to the rock structural plane，which fills the void space on the rock structure surface as ductile gouge layer，weakens the hardness of the surface asperity and reduces the friction strength of the rock structure structural plane. The existence of crude oil also makes the friction strengthening effect of the structural plane and the self-locking effect of asperities weak，and the structural plane is more prone to undergo dynamic slip compared to structural plane with dry or wet interfaces. The interface type controls the increase of friction coefficient and the slip rate at the start of dynamic slip. The friction coefficient of dry，wet and crude oil rock structural planes increased by 5%，11.2% and 0.7% respectively during activation process，and the slip rate at the start of dynamic slip are 1.1 mm/s，0.27 mm/s and 0.023 mm/s respectively. Our research may provide a theoretical basis for evaluating the fault instability of structural plane with different interface types in the oil and gas reservoirs，and have important implications for better understanding the occurrence of extraction induced fault activation.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[HU Minghui，LIU Richeng，LI Shuchen，ZHU Xinjie，QIU Kai]]></author>
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<title><![CDATA[Differentiation characteristics and mechanism of hydraulic erosion of soil-rock mixtures with different rock content]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42640.shtml]]></link>
<description><![CDATA[Hydrodynamically induced colluvial landslide is one of the main geological disasters in southwest China. It is significant to investigate the erosion differentiation mechanism of soil-rock mixtures for revealing the landslide mechanism in depth. The rock content is the most important factor affecting the erosion differentiation characteristics of soil-rock mixtures. Based on the seepage erosion tests of soil-rock mixtures with different rock content，the erosion differentiation characteristics and mechanism of soil-rock mixtures are revealed. The results show that there are four random states in the process of seepage erosion of soil-rock mixtures：erosion intensification，erosion mitigation，internal block structure reorganization and erosion stability. The rock content has a significant effect on the erosion differentiation characteristics. The permeability coefficient of soil-rock mixture increases at first，then decreases subsequently，and then increases again with the increasing rock content，and the lowest value is observed at the rock content of 60%，which was less than 1&times;10－2 cm/s and cause a slight fluctuation. Whereas，the permeability coefficient of soil-stone mixtures at a high rock content is nearly unchanged before and after seepage，with a change rate less than 10%. The amount of erosion increases with the increasing hydraulic gradient. On the basis of change of erosion amount，the seepage erosion is divided into three stages：violent erosion，slow erosion and stable seepage stage. The critical hydraulic gradient decreases with increasing rock content. The rock content affects the permeability of the soil-rock mixtures by affecting the filling form of the soil-rock structure，and the full-filled structure has the best impermeability，which provides ideas and references for revealing the mechanism of hydraulic instability of the colluvial slope.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[YANG Zhongping1，2，3，LI Yonghua1，LI Shiqi1，LIU Haoyu1，GAO Yuhao1]]></author>
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<title><![CDATA[A novel rockburst proneness index based on maximum energy dissipation rate]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42617.shtml]]></link>
<description><![CDATA[Rockburst proneness evaluation provides a basis for rockburst risk assessment in deep tunnels. Based on energy dissipation characteristics of the complete stress-strain curve of rocks under uniaxial compression，a new evaluation index for rockburst proneness，the maximum energy dissipation rate(the maximum value of time derivative of the dissipated energy density)，was proposed. The rationality of proposed index was explained from three perspectives：stability criteria，experience，and definition of rockburst proneness. To quantitatively calculate the proposed index，an elastic-brittle-damage constitutive model considering void compaction and initial damage was established. To verify the applicability of the proposed index and damage model，uniaxial compression and cyclic loading and unloading tests were conducted on four different rocks(basalt，granite，limestone，and sandstone) under rigid and flexible testing machines. Based on the orthogonal tests，correlation analysis，and range analysis，the internal relationship between the proposed index and other rockburst proneness indices was revealed. The major findings are as follows. (1) There exists a maximum energy dissipation rate in the post-peak stage of rock stress-strain curve，which can be used as an inherent stability indicator to evaluate rockburst proneness. The advantage of this indicator is that it can comprehensively consider the pre-peak energy storage and consumption characteristics and post-peak characteristics. (2) The proposed elastic-brittle-damage model effectively describes the nonlinear mechanical behavior and intrinsic energy evolution characteristics of brittle rock(including input energy density，elastic strain energy density，and dissipated energy density). The theoretical curve is in good agreement with the experimental values，and the proposed maximum energy dissipation rate index can be accurately calculated using proposed model. (3) The calculation results of the maximum energy dissipation rate index for different rocks are consistent with the actual rockburst intensity observed in the experiment，verifying the reliability of proposed index. (4) Among the energy-based rockburst proneness indices，the proposed index has the strongest correlation with residual elastic energy index(with a correlation coefficient of 0.940)；the proposed index considers the degree of influence of rock brittleness on rockburst proneness more reasonably. The research method adopted in this study provides a new approach for proposing rockburst proneness indices and analyzing their interrelationships，and the research results provide a scientific basis for the reasonable evaluation of rockburst proneness.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Rujiu1，ZHANG Yanjie2，GAO Tong3，LI Mei2，LIU Yaoru1，ZHANG Kai1]]></author>
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<title><![CDATA[Compressive failure response and thawing-induced softening effect of frozen ice-sandwiched rock mass]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42614.shtml]]></link>
<description><![CDATA[With the continuous warming of climate，thermal and melting degradation of perennial frozen layers in the Qinghai-Tibet Plateau，Alps and other high altitude areas leads to a large number of rock mass instability disasters. To study the &quot;softening effect&quot; of mechanical properties of frozen ice-sandwiched rock mass upon thawing is a key premise to reveal the thermal melting instability mechanism of frozen rock mass. In this paper，a series of uniaxial compression tests were carried out on frozen rock mass with different crack angles and melting temperatures，and acoustic emission and high-speed photography methods were used to monitor the failure process. The results show that：(1) the uniaxial compressive strength of the samples decreases first and then increases with the increase of the crack angle &theta;.(2) The uniaxial compressive strength of the sample decreases gradually with the increase of temperature，which can be divided into three stages： rapid reduction stage(－20 ℃～－6 ℃)，fluctuation decline stage(－6 ℃～－1 ℃) and strength plunge stage(－1 ℃～0 ℃).(3) The samples with different crack angles have three failure modes：the ice layer is crushed as a whole，which is brittle failure；The obvious plastic deformation occurs after the ice is broken，which is ductile failure. Cracks in the middle of the ice layer extend to the upper and lower ice-rock interface，and relative slippage occurs along the interface of the upper and lower rocks. The whole sample is broken，which is brittle failure.(4) Under the condition of thermal melting，the failure mode of fractured ice-sandwich rock mass can be divided into two types：the cracks in the middle of the ice layer expands to the upper and lower ice-rock interface，the relative slip of the upper and lower rocks occurs along the interface，and the whole sample is broken(－20 ℃&le;T&le;－6 ℃ or －1 ℃&le;T&le;0 ℃)；Obvious plastic deformation occurred after the ice layer was broken，and no whole fracture occurred(－6 ℃＜T＜－1 ℃). Through theoretical analysis，the influence mechanism of crack Angle on the compressive strength of fractured ice-sandwich-rock mass is mainly that the failure mode of fractured ice-sandwich-rock mass changes from vertical splitting failure of ice sheet to shear failure along ice-rock interface and shear failure along ice layer with the increase of crack Angle. Based on the results of NMR one-dimensional imaging，the content of unfrozen water at the ice-rock interface increases continuously during the heating process，that is，the strength of the ice-rock interface decreases continuously，which leads to the temperature dependence of the strength variation of fractured ice-rock mass.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Qiang1，JIA Hailiang1，YANG Gengshe1，YANG Liu2，YANGY Chunmei1，LIU Xianhuan1]]></author>
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<title><![CDATA[Shear fracture &ldquo;slow-release&rdquo; structure of coal mass and its evolutionary characteristics]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42613.shtml]]></link>
<description><![CDATA[The stratification and bedding characteristics of the coal-bearing construction make the surrounding rock more of a shear disaster. To further investigate the shear fracture behaviour of coal rock masses under cyclic loading conditions，uniaxial compression tests on sandy mudstone were carried out using constant amplitude cyclic and stepwise linear cyclic loading and unloading methods in conjunction with CT scanning. The &ldquo;Domino&rdquo; structure of shear rupture of rock samples and its evolutionary characteristics were analysed by means of the rupture morphology and the stress-strain curve of the whole process. The results show that：under uniaxial compression and constant amplitude cycles and stepwise linear cycles，shear failure occurs in all rock samples. Moreover，the shear fracture zone formed by the failure of rock samples under stepwise linear loading and unloading cycles includes several strain localization zones with a &ldquo;Domino&rdquo; structure，and the stress-strain curve corresponding to the failure process shows a special &ldquo;hysteresis-reciprocation-hysteresis-reciprocation&rdquo; oscillation fluctuation. The strain localization zone presents the evolution process of nucleation，cracking，expansion，decay and conduction. The rotating-gyration motion of the fragmented block with the &ldquo;Domino&rdquo; structure causes multi-stage dissipation of the input energy and elastic storage energy after the peak in the friction of the block，which prolongs the damage time and has a significant &ldquo;slow release&rdquo; effect. The shear crack morphological evolution and stress&ndash;strain concealment information cooperate with each other to divide the shear failure process into six failure stages，namely：crack initiation micropropagation(I)，crack initial propagation(II)，primary shear crack propagation(III)，Crack propagation metastable(IV)，rapid crack propagation(V)，accelerated failure(VI). The &ldquo;Domino&rdquo; structure is a unique form of shear failure，and the energy &ldquo;slow release&rdquo; effect it plays may be a new idea for coal mine roadways to use the surrounding rock structure to relieve pressure and protect the roadway.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Xiangyu1，2，CHAI Zhaoyun1，XIAO Chang1，SHEN Yuxu1，XIN Zipeng1，LI Tianyu1，SUN Haocheng1，YAN Ke1，Liu Xinyu1，DUAN Biying1]]></author>
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<title><![CDATA[Dynamic response analysis of Dagangshan arch dam under the Sichuan Luding Ms 6.8 earthquake#br#]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42612.shtml]]></link>
<description><![CDATA[In order to study the seismic dynamic response law of high arch dam，based on the measured seismic waveform of Dagangshan arch dam with a height of 210 m and a distance of 21 km from the epicenter in the Sichuan Luding MS 6.8 earthquake，the seismic response characteristics and laws are analyzed by time domain and spectrum analysis methods. The results show that under the main shock excitation of the Luding earthquake，the peak acceleration(PGA) of the arch dam along the river is 586.63 cm/s2(6 # dam crest)，and the PGA of the bedrock along the river is 229.18 cm/s2. The acceleration distribution is generally greater than the horizontal and vertical directions，and the dam body is greater than the resistance body on both sides. The dynamic response of the dam is the most significant along the river. As the elevation increases，the dynamic amplification effect gradually increases，and the maximum amplification factor reaches 4.2 times(6 # dam crest).The results of spectrum analysis show that the main frequency of the earthquake is about 1.73 Hz，and the main frequency of the dam above 1081 m is between 1.52 and 1.75 Hz，which is close to the modal frequency of the dam. This is one of the reasons why the dam has a strong sense of earthquake. Combined with the dynamic response analysis of typical earthquake dams in recent years，earthquakes with large magnitude and far epicenter distance are more likely to stimulate the low-frequency dynamic characteristics of dams. The relevant results can provide reference for post-earthquake dam safety assessment，seismic design and research of high arch dams.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[JIANG Dejun1，HUANG Huibao1，2，QI Yaoguang3]]></author>
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<title><![CDATA[Identification research on characteristic stress in front of peak based on acoustic emission and wave velocity variation of sandstone under triaxial loading]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42542.shtml]]></link>
<description><![CDATA[In order to accurately identify the pre-peak characteristic stress in the process of rock loading under different confining pressures，the pseudo triaxial tests with confining pressures of 0，10，30，50 and 70 MPa were carried out on the GCTS RTX-3000 testing machine using sandstone standard samples. The ultrasonic testing system and acoustic emission acquisition system were used to monitor at the same time，and the variation law of ultrasonic wave velocity and the distribution characteristics of acoustic emission location events during sandstone loading were obtained. A method that can shield ultrasonic interference signals from acoustic emission dates was proposed. The results show that the compression and shear wave velocities of the sample show a quadratic function relationship with the increase of confining pressure. With the increase of axial pressure，the compression and shear wave velocities of the sample show a law of growth，stability and decline. The shear wave velocities always show a downward trend before the compression wave velocities，and the shear wave is more sensitive to damage than the compression wave. The pre-peak characteristic stress can be accurately determined by comparing the change rules of volume strain，acoustic emission，ultrasonic and dynamic elastic parameters. The closure stress corresponds to the end of the rise of the shear wave velocity，the initiation stress corresponds to the beginning of the fall of the shear wave velocity and the inflection point of the dynamic elastic modulus，and the damage stress can be determined jointly by the beginning of the decline of the compression wave velocity，the rapid rise of the acoustic emission signal and the inflection point of the volumetric strain. Acoustic emission positioning can directly reflect the failure mode of the sample. Under low confining pressure，the sample will undergo split shear mixed failure，while under high confining pressure，the sample will undergo shear failure. This study is helpful to accurately identify the pre-peak characteristic stress of rock under load，and deeply understand the damage characteristics of rock under different stress conditions，which is of great theoretical significance to the stability evaluation of rock mass in deep underground engineering.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[ZHANG Xulong1，ZHANG Sheng1，2，WANG Longfei1，RONG Tenglong1，2，ZHOU Rui1]]></author>
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<title><![CDATA[Experimental study on load bearing performance of stone columns under different reinforcement methods]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42459.shtml]]></link>
<description><![CDATA[An model test set of gravel pile composite foundation was fabricated，and 11 sets of model tests of reinforced gravel pile composite foundation and 2 sets of unreinforced comparison tests were carried out. The composite foundation bearing capacity，pile-soil stress ratio，bearing capacity improvement rate and pile bulge deformation under different parcel length，reinforcement spacing and reinforcement combination methods are researched. The test results show that compared with the traditional gravel pile，the bearing capacity of the composite foundation is significantly improved by reinforcement，and the vertical reinforcement effect of the full-length wrapped is the most significant；The reinforcement method with larger composite foundation bearing capacity improvement corresponds to larger bearing capacity improvement rate and pile-soil stress ratio. The improvement rate of bearing capacity increases with the increase of reinforcement length and reinforcement spacing；The pile-soil stress ratio of the composite foundation fluctuates with the increase of settlement. And increases with the reduction of reinforcement spacing and the increase of reinforcement length；There are some differences in the deformation law of pile body under different reinforcement methods. The bulging deformation of pile body with full-length wrapped vertical reinforcement method is relatively uniform and the deformation is small，which has better effect on improving the bearing capacity of composite foundation and inhibiting the bulging deformation of pile body.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LI Lihua1，2，CAO Yu1，2，LIU Juqiang1，2，XIAO Henglin1，2，ZHANG Dongfang1,2，LIU Yiming1,2]]></author>
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<title><![CDATA[Two-phase coupling model based on DEM-SPH and its application in simulation of water inrush disaster in TBM tunnels]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42286.shtml]]></link>
<description><![CDATA[Water inrush disaster is one of the most common geological disasters in tunnel construction，which is a complex hydro-mechanical coupling process of groundwater and geotechnical media. This study proposed a Discrete Element Method-Smoothed Particle Hydrodynamics(DEM-SPH) coupling method to simulate two-phase flow process of the disaster. Based on the water inrush disaster of 3# TBM tunnel of Yinsong Water Supply Project in Jilin Province，numerical simulations of evolution process of water inrush disaster were carried out through the proposed two-phase coupling method. In simulation，multiphase flow state of solid and fluid media as well as their mass flow rate during the process of water inrush disaster were monitored and analyzed. Finally，the normal impact force on TBM Cutterhead due to water inrush disaster and its torque power was recorded and analyzed. It shows that the normal impact force dramatically increases at sudden of water inrush and then maintain at a relative low level，while the torque power continued to increase as the process of water inrush. These results will provide valuable guidance for the treatment of similar water inrush disasters in TBM tunnels.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[LIU Cong1，2，LI Liping1，2，ZHOU Zongqing1，2，GAO Chenglu1，2，BAI Songsong2，SUN Jiwei2，LIU Yuhan2]]></author>
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<title><![CDATA[Asymmetric floor heave mechanism and pressure relief control in composite bottom-slab roadways based on the "three-hinged arch-spring" model]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42237.shtml]]></link>
<description><![CDATA[In order to solve the problem of asymmetric floor heave of roadway and the potential of inducing kinetic events in dynamic pressure roadways，this paper established a "three-hinged arch-spring support" model based on the geometry and force characteristics of asymmetric roadway deformation，and analyzed the energy dissipation characteristics of the system and the sufficient discriminatory conditions for abrupt destabilization at the cusp of the total potential energy function of the system. The research showed that：The deformation of the equilibrium curve takes two forms when along path I，the deformation is linear and progressive，and no large energy release kinetic event occurs. When along path II，the deformation is a non-linear and abrupt floor heave of roadway，where the lithology，dimensions and lateral stress of the roadway bottom are the key factors affecting the system instability，and the floor slab kinetic event can be prevented by pressure relief. Therefore，the technique of cutting the roof to unload the floor heave of roadway is proposed，the mechanism of pressure unloading is analyzed，and pressure unloading tests are carried out in the Caojiatan coal mine. The results prove that cutting the roof is done by changing the support form of the overhanging roof plate to shorten the collapse step of the roof plate，thus realizing the horizontal and vertical pressure unloading and the release of the collected energy in the quarry，and the horizontal pressure unloading is more obvious than the vertical，thus effectively controlling the deformation of roadway floor.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XU Xiaoding1，2，ZHOU Yuejin1，GAO Yubing2，FU Qiang2，WEI Xingjian2]]></author>
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<title><![CDATA[Study on the correlation between the lateral facing deformation and factor of safety for tiered GRS wall]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42214.shtml]]></link>
<description><![CDATA[To investigate the lateral facing deformation characteristics and the relationship between the maximum deformation and stability of GRS wall in a tiered configuration，a validated finite difference numerical method was used to compute the maximum lateral facing deformation and the maximum tensile forces mobilized in each layer reinforcement，which were utilized to determine the factor of safety(FS) of the corresponding GRS walls，and then a parametric study was conducted to analyze the effect of properties of backfill and foundation soil，reinforcement properties，and configuration mode of tiered GRS wall on deformation and stability. The computed results showed that：(1) The other parameters of two-tiered GRS walls remain unchanged，increasing the friction angle or cohesion，the GRS wall becomes more stable，and the maximum lateral facing deformation and the maximum tensile force mobilized in reinforcement decrease and the FS increases. Increasing reinforcement length in upper or lower wall results in a reduction of lateral facing deformation and an increase of FS，and when reinforcement lengths in upper or lower wall reach the critical length，e.g. 0.7H(H，the total wall height) or 0.6H，the maximum lateral facing deformation and FS values tend to be stable. Reducing the vertical spacing of reinforcement or increasing the reinforcement stiffness caused a decrease in lateral facing deformation and an increase in FS.(2) For a multitiered GRS wall with equally individual wall height，with the increase of the offset distance，the maximum lateral deformation tends to decrease and then to be stable. The critical offset distance，beyond which the adjacent tiers wall functions independently，is 1.2 times the individual wall height for the recommended friction angle(? = 34°) by guidelines.(3) For a multitiered GRS wall with the same total wall height and normalized offset distance，increasing the number of tiers wall results in a decrease in maximum lateral deformation and FS，which then tend to be increasing when the number of tiers reaches a specified value. When the wall height ratio of the upper and lower wall is no great than 1，the change of the ratio does not affect remarkably the lateral facing deformation. Once the upper wall height is greater than the lower wall，the maximum lateral facing deformation in the upper wall increases significantly. In addition，increasing the total wall height causes an obvious increase in lateral facing deformation，and consequently，the FS decreases.(4) Based on the calculation results of two-tiered GRS walls，an empirical function is proposed to build the correlation between FS，normalized maximum lateral deformation，and normalized offset distance. It is helpful for engineers to evaluate the stability of a two-tiered GRS wall via the quantified maximum lateral deformation.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[GAO Shan1，XIAO Chengzhi1，DING Luqiang1，YU Hongxing2]]></author>
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<title><![CDATA[Study on the weightless-expansion mechanism of red-layer mudstone by heat treatment temperature]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract42212.shtml]]></link>
<description><![CDATA[In this study，drying experiments at different temperatures were conducted to study the variations in the quality，fracture，pore，microstructure and expansion of upper-Shaximiao Formation red mudstone in eastern Sichuan Province. Field emission scanning electron microscope(SEM)，N2 adsorption measurement and digital radiography(DR) were used to evolution micro-structure，meso-pore and macro-fracture of rock samples during heat treatment，aiming to obtain the mass loss and expansion rules of rock samples reveal the influence of heat treatment on the expansion mechanism of red mudstone. The results show that：(1) The mass loss of rock samples presents two patterns as "rapid water loss-slow water loss" and "slow water loss" with the increase of heat treatment temperature. The complete water loss of the red mudstone requires a heat treatment temperature greater than 130 ℃；(2) Clay minerals exhibit interlayer opening and cracks along layers after high-temperature heat treatment，while they mainly show intralayer cracks after low-temperature heat treatment. The contribution of heat treatment temperature to macro cracks after heat treatment is low less than primary fissure；(3) The fine particles (0.5～2 nm) in rock pores increase significantly with the decrease of heat treatment temperature，and the number of these particles reaches the peak at 110 ℃. Heat treatment temperature has an obvious effect on the micro-pore sizes of rocks. Compared with the "single peak" distribution of pores in natural state，the pore distribution after the high temperature heat treatment presents a bimodal type. (4) The expansion pattern under the low temperature treatment is mainly controlled by macro-fractures，while the expansion pattern under high temperature treatment is dominantly controlled by the macro-fractures and micro-pores. In addition，increasing the heat treatment temperature can significantly increase the curve slope and final expansion in the “rapid expansion” stage. The results reveal the characteristics of micro-structures and micro-pores and the development of macro-fractures under different heat treatment conditions and discuss the influence of heat treatment temperature on the expansion processes of upper-Shaximiao Formation red mudstone，which may provide a new insight into predicting the drying degree of mudstone and provide a reference to the correction of final expansion rate under specific heat treatment conditions.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[XIE Zhuowu1，LING Sixiang1，LIAO Xin1，WU Xiyong1，ZHAO Siyuan2，CHEN Ming3，DUAN Qian4]]></author>
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<title><![CDATA[Stress distribution and failure characteristics of floor of a longwall panel with a negative gate pillar]]></title>
    <link><![CDATA[https://rockmech.whrsm.ac.cn/EN/abstract/abstract32124.shtml]]></link>
<description><![CDATA[To study stress distribution and failure characteristics of floor of a longwall panel with a negative gate pillar，coupled finite and discrete element numerical modelling method was adopted to construct a FLAC-PFC coupling numerical model. Spatiotemporal evolution of floor stress distribution，failure characteristics and effect of caved rock accumulation on floor stress and failure were analyzed throughout the process from setup room excavation to compaction of caved rock in gob to roof strata settlement. Based on elastic mechanics，a mechanical floor model was established to derive failure depth. The results show that：(1) Asymmetric accumulation of caved rocks in gob and asymmetric collapse of roof result in asymmetry of stress and failure of floor. (2) A "bottleneck" structure is formed by asymmetric failure of the floor and rotary cave-in of key blocks of roof，which hinders the further asymmetric slip of gob rocks. (3) The floor stress distribution under the influence of asymmetric accumulation of gob rocks presents a spacial distribution of "large top and small bottom". And the stress concentration on both sides of the gob increases first and then decreases over time，and the floor stress experiences a transition of "compressive-tensile-compressive". (4) Numerical simulation，theoretical calculation and field measurement results verify the asymmetric characteristics of stress and failure of floor caused by asymmetric accumulation of gob rocks. The study serves to provide theoretical support and scientific basis for determining location of gob side entry and its surrounding rock control of future adjacent panel with a negative gate pillar.]]></description>
<category><![CDATA[Forthcoming Articles]]></category>
<author><![CDATA[WANG Pengfei，LIU Jianan，FENG Guorui]]></author>
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