Relying on microseismic monitoring，deep learning and virtual simulation technology，a system and platform for the automatic integrated processing of tunnel microseismic information and intelligent warning of rock bursts is established in this paper. Both a microseismic multi-classification model based on bimodal feature extraction，and a dual-task model of noise reduction and arrival pickup of a waveform based on deep convolutional encoding and decoding network are proposed，and a microseismic positioning algorithm based on the gravity search method is put forward，for realizing automatic，efficient and accurate processing of tunnel microseismic classification，noise reduction，picking，positioning and source parameter calculation. Selecting cumulative apparent volume and energy index source parameters as key indicators，a parallel sequence prediction model for microseismic parameters and a prediction and warning model for rock burst incubation stage based on LSTM multi-variant network are established，which achieves early warning of the current future state and time evolution of rock bursts. Meanwhile，the integration and display of tunnel site geographic information，geological models，tunnel models and disaster(microseismic) information are achieved based on the three-dimensional visualization framework Cesium，forming a tunnel microseismic monitoring and rock burst warning system that integrates microseismic information collection module，microseismic information cloud processing module，and rock burst prediction and warning module. The system is applied to the rock burst disaster section of the Daxiagu Tunnel of Ehan Expressway，achieving automatic，efficient and accurate processing of massive microseismic data，and verifying the effectiveness of the automatic integrated processing of tunnel microseismic information and the intelligent warning technology system for rock bursts.

Sandy dolomite is widely distributed in underground engineering in southwest China. Severely and completely sandy dolomite has a broken rock mass structure and poor water stability. During the construction of the sandy dolomite tunnels，disasters such as collapse，water inrush and water-sand inrush occurs frequently. However，the research on the gestation，formation and occurrence of sandy dolomite tunnel disasters is almost empty，and special systematic research needs to be carried out. This paper collected more than eighty cases of sandy dolomite tunnel collapse，water inrush and water-sand inrush. In-depth investigation and analysis of the geologic and structural conditions of the occurrence of related disasters were performed. From the bad geological conditions and the main influencing factors of disasters，the hazard-causing structures of the sandy dolomite tunnels are divided into four categories including eight types. The first category is fault，including three types，i.e.，the anhydrous fault type，the water-conductive fault type and the water-resistive fault type. The second category is fracture，including the monoclinic fracture type，the interlayer fracture type and the sandy strip type，The third category is fold，including the anticline type and the syncline type. The final category is the karst pipeline. These hazard modes are divided into three types based on the time evolution characteristics of disaster occurrence，such as the immediate revealed type，the progressive failure type and the intermittent failure type. From the perspective of the main engineering site where the disaster occurs，the tunnel is divided into twenty failure modes of four parts. And the corresponding engineering control measures are put forward. Finally，the case analysis and control measures of the typical disaster tunnel section of the Water Diversion Project in Central Yunnan are introduced. Consequently，the research results have important significance for the design，construction，risk assessment and preventive control of underground engineering in sandy dolomite.

When active faults experience tectonic movements，tunnels crossing these active faults will undergo varying degrees of structural damage and failure. Existing experimental setups that simulate the fault displacement of tunnels crossing active faults are mostly designed for shallow-buried tunnels and do not consider deep-seated stress conditions. This limitation has impacted the applicability of their test results to deep-buried，high-stress tunnel projects. Given this，the development of an experimental apparatus capable of simulating complex fault-displacement mechanisms under high in-situ stress conditions becomes a crucial component. This study，in conjunction with the characteristics of large lifeline projects crossing active faults in the strong seismic zone of western China，determined the parameters required for the experimental apparatus. We have successfully developed this apparatus and utilized it to investigate the differences in lining damage characteristics between deep-buried and shallow-buried tunnels.The results show that：(1) tunnel structures crossing active fault zones in the strong seismic regions of western China exhibit features such as significant burial depth，high in-situ stress，and complex fault displacement. Consequently，the design parameters for the experimental apparatus were determined，including a confinement pressure of 0.8 MPa，a horizontal fault offset of 20 cm，and a vertical fault offset of 10 cm. (2) By conducting free-field and tunnel model fault-displacement experiments，it was confirmed that the equipment can effectively simulate pure strike-slip，dip-slip，and strike-slip/dip-slip-coupled fault movements. Moreover，it was observed that the confining pressure remains stable during the fault movement process，thereby achieving the objectives of this research and equipment development. (3) The tunnel fault-displacement tests yielded the following outcomes：Deep-buried tunnels exhibited significant compressive deformation，resulting in larger areas of damage. Shallow-buried tunnels，on the other hand，experienced shearing at the fault zone，leading to more severe structural damage. Moreover，when the fault was oriented at a small angle to the tunnel axis，the level of damage to the tunnel increased. The development of this equipment provides a crucial foundation for investigating the impact of complex fault mechanisms on tunnels crossing active faults in high-stress environments.

Taking Banbiyan dangerous rock in the Three Gorges Reservoir Area as a research object，the formation process and characteristics of the shear band in the dangerous rock were summarized. In this paper，laboratory tests and numerical simulation were used to study the shear transfixion mechanism and mechanical properties of the shear band-bedrock interface from a macro-meso perspective. The results show that：(1) the shear band is the main controlling factor of the dangerous rock instability，and the internal filling material is laminar and unbonded. (2) Under the condition of constant normal stress，the failure modes of the interface can be summarized as step root tensile fracture-step climbing，rock slab damage-step shear fracture，rock slab crack coalescence-step shear broken. (3) Six typical stages can be observed in shear stress-shear displacement curves，including the compaction stage，the oblique crack occurring stage at the step root near the loading end，the approximate elastic deformation and micro-crack propagation stage，the step near the loading end shear fracture stage，the remaining steps shear fracture stage，and the residual stage. (4) The peak shear strength and the residual strength of the interface increase with the increase in normal stress，layer thickness and step height. The vertical cumulative displacement decreases with the increase in normal stress and increases with the increase in layer thickness and step height. (5) The interface crack number curve shape is“S”type，which can be divided into three stages，including the crack number slowly increasing stage(rock slab surface wear)，the rapid crack propagation stage(steps shear fracture)，and the crack number keeping stable stage(residual friction). The curve change trend of particle strain energy and cementation strain energy is similar to that of the shear stress-shear displacement curve，and the total energy，friction energy，and damping energy increase with the increase in shear displacement. The research results are of reference significance to the study of the mechanical properties of the shear band and the stability of the dangerous rock.

The mechanical properties of coal are heavily influenced by the primary bedding fractures. To investigate the crack expansion and destabilization mechanism of liquid nitrogen( ) low-temperature fractured layer coal，a thermal-fluid-solid-damage coupling model was established based on meso-element theory and damage mechanics. The evolution of coal damage，permeability and temperature were analyzed throughout the fracturing process，along with the distribution characteristics of crack propagation in layer coal induced by fracturing during various stress ratios，as obtained by COMSOL software simulation. The results indicate that the temperature of the coal in contact with near the drill hole drops sharply to form a small range of ultra-low-temperature zone，which generates thermal stresses exceeding the tensile strength of the coal，and produces damage around the drill hole and destroys the damage area in the initial stage of injection(5 s). With the increase of injection pressure，multiple main cracks appeared inside the coal. The main cracks were mainly developed along layer direction and generated secondary fissures and a complex damage area was formed around the borehole. The number of coal damage begins to increase，accompanied by a corresponding increase in permeability. With a continuous increase in injection pressure，the coal enters an instability stage. A large number of cracks extensively penetrate the coal specimen，leading to coal damage. During this process，both permeability and fracture pressure gradually reach the peak values. The coal damage，fracture pressure，and permeability exhibit a trend of increasing and then decreasing with increasing layer angle，and reach the maximum value when the layer angle is 45°. The coal damage，fracture pressure and permeability reached the maximum when the stress ratio was 0.5，decreased dramatically when the stress ratio increased from 0.5 to 1，and gradually leveled off after the stress ratio exceeded 1. The existence of coal layer has a greater influence on the initiation pressure of fracturing of coal and the change rule of initiation pressure is similar under the conditions of different layer angles. With the increase of layer angle，the initiation pressure shows a U-shaped change rule，and the initiation pressure shows an increasing trend with the increase of stress ratio. The research results provide a basis for further mastering the fracturing coal technology and determining the process parameters.

Open pit mines are widely distributed in China，and disasters such as rock collapses and landslides in open pits are very common due to both natural and engineering factors. Open pit slopes often cover a large area with a long service period and therefore their geological conditions can be very complicated. Considering these characteristics，this study takes the Fushun west open pit mine as the engineering background and develops a multiple-dimensional collaborative monitoring and early warning system for open pit slopes using multi-source information fusion technique. The meteorological environment，surrounding surface，open pit slope and the affected infrastructures were determined as the monitoring objects based on the mining location，engineering geological conditions and the distribution characteristics of potential disasters. A series of monitoring indicators reflecting the overall and local deformation characteristics of the open pit slope and external environmental characteristics were selected，and then the multi-dimensional collaborative monitoring system was established，which can implement the full-time monitoring，cyclical monitoring and urgent monitoring of potential hazards for both the open pit slope and surrounding buildings. By analyzing the evolution characteristics of slope disasters in Fushun west open pit，the displacement rate of the slope was taken as an early warning indicator，and thus three warning levels with corresponding threshold values were identified for typical slope hazards. Based on existed geographic information，a multi-parameter，multi-dimension and multi-sequence monitoring database for geological hazards of open pits was constructed using techniques including GIS，the Internet of Things，etc.，and finally，a platform for visualization and early warning of open pit slope hazards was developed. The results show that the multiple-dimensional collaborative monitoring and early warning system can quickly and accurately recognize the potential geological hazards in the mining area and significantly improve the warning efficiency of open pit slope disasters. The findings may provide reference and guidance for the prevention and mitigation of slope disasters at open pit mines in China.

盐岩地下储气库运行压力的设定不仅关乎其长期稳定性和密闭性，还影响储气规模和调峰能力，因此，确定运行压力区间对盐穴大规模储能具有重要的工程意义。以保障储库长期安全性为基本原则，总结、归纳以密闭性和稳定性为主控影响因素的上、下限运行压力设定准则，进而为运行压力设定提供依据。基于盐岩储气库围岩与存储介质之间的相互作用机制和运行压力设定准则，建立考虑损伤和渗透演化的流–固耦合分析模型，通过数值开发将其应用至金坛某实际盐岩储气库的密闭性和稳定性同步分析中，探讨储库围岩损伤和渗透率演化规律及影响因素，确定目标储库的几个关键设计参数，如运行压力区间、矿柱宽度、顶板厚度等。研究结果表明：运行压力对盐岩储气库的渗漏范围和蠕变收缩率的影响是截然相反的，其中，渗漏范围与运行压力呈正相关的幂函数关系，蠕变收缩率与运行压力呈负相关的指数函数关系，密闭性控制着储库上限压力，稳定性控制着储库下限运行压力。围岩损伤演化主要受应力水平和岩石变形性质影响，渗透率演化取决于有效平均应力和塑性损伤的竞争结果，只有当塑性损伤占主导影响时才可能诱发渗透率激增现象。考虑渗透参数演化比不考虑参数演化得到的气体渗漏范围大约5%，该影响主要集中在腔壁边界10 m范围。

To investigate the effect of acidic fracturing fluid on the fracture behavior and energy dissipation of anthracite under impact load，a split Hopkinson pressure bar(SHPB) impact loading system was used to conduct model-I dynamic fracture toughness tests on notched semi-circular bending(NSCB) anthracite samples treated with acidic fracturing fluid and water-based fracturing fluid under varying impact pressures. The dynamic crack propagation process of coal samples was recorded by high-speed camera device. Combined with Image J analysis software and PCAS image recognition system，the macroscopic crack propagation trajectory and probability entropy of micro pores in coal samples were quantitatively analyzed. By comparing the incident energy，absorbed energy，fracture energy and residual kinetic energy of anthracite samples under different impact pressures and various fracturing fluids，the energy dissipation law of dynamic fracture process of acid corroded coal samples under impact loads was obtained. The results show that the dynamic fracture toughness of coal samples in natural state is the largest，and the fracture toughness of coal samples treated with acid fracturing fluid is lower than that of water-based fracturing fluid when the impact pressure is higher than 0.35 MPa. The prefabricated cracks in acidic fracturing fluid-treated coal samples are more likely to initiate under higher loading air pressure conditions. The difference between the fracture energy required by acid fracturing fluid group and that of water-based fracturing fluid group increases with the increase of loading pressure. The higher the loading air pressure，the less fracture energy required for the acid fracturing fluid treated coal samples compared to the water-based fracturing fluid group. The pore probability entropy value of coal sample fracture surface increases with the increase of impact pressure，and the fracture surface morphology of coal sample transforms from compact and neat to loose and porous due to the action of acid fracturing fluid. The dual mechanism of weakening and enhancing the fracture behavior of anthracite coal by fracturing fluid under different loading rates was explored，and a microscopic fracture mechanics model considering the loading rate was established based on the dual nature of fracturing fluid and the theory of linear elastic fracture mechanics. The research results provide experimental support for the investigation of crack initiation and propagation mechanism of acid fracturing for anthracite coal，and provide theoretical guidance for the design of acid fracturing in coal seam and the control method of complex fracture network.

Shear tests of three-dimensional rough joint surfaces were conducted under superimposed actions of sinusoidal cyclic normal dynamic loads and sinusoidal cyclic shear displacements. The effects of initial normal static load( )，dynamic normal load amplitude( )，dynamic normal load frequency( ) and the number of shear cycles (N) on the shear properties were explored. With an increasing of or ，the variation range of the normal load for the joint surfaces gradually increases. Within a shear displacement cycle，the shear load experiences a variation of fluctuating increase→fluctuating decrease→fluctuating increase. The peak shear load in stable states increases by 4.90 times and 65.12%，respectively，with an increasing of and ，implying a gradually enhanced shear resistance capacity. However，as increases，the progressive accumulation of damage on the joint surfaces results in a gradual reduction in the peak shear load，and the moment when the peak shear load occurs gradually moves forward. The peak shear load in stable states decreases by 17.49%. Within a shear displacement cycle，the normal displacement of joint surfaces shows a variation trend of fluctuating increase→fluctuating decrease→secondary increase→secondary decrease. When the joint surface shears away from the initial position，the continuous “climbing effects” of the surface asperities lead to a gradual increase in the normal displacement. A significant negative correlation between the normal displacement and normal load for the joint surfaces is recognized，and the maximum normal displacement lags behind the maximum shear displacement by a quarter of a normal load period. As N increases，the continuous wear and deterioration of the joint surfaces lead to an exponential decrease in the maximum normal displacement. The maximum normal displacement exhibits change characteristics of gradually decreasing with ，gradually increasing with ，and initially increasing and then decreasing with ，respectively. The surface roughness coefficients of joints after shearing decrease by 57.79% and 43.26% with and respectively，while shows a variation of first increasing and then decreasing with at 1 Hz as the inflection point.

Fluid-solid phase transition characteristics of quick-setting grout has an obvious effect on rock fissure grouting diffusion. With the objective to study rock fissure grouting diffusion mechanism of quick-setting grout，cement- sodium silicate grout(C-S grout) was regarded as the typical quick-setting grout in this paper. Bingham rheological constitutive model with yield stress and viscosity changing with reaction time simultaneously was adopted to describe fluid-solid phase transition characteristics of quick-setting grout. Time-dependent equations of yield stress and viscosity of C-S grout were acquired based on laboratory test. Rock fissure grouting diffusion model of quick-setting grout was established. Rock fissure grouting simulation tests of C-S grout with constant injection rate were done. Injection pressure and spatial distribution of grout pressure in whole grouting process had been acquired. Verification of theorical model had been done based on test results. Temporal and spatial distribution characteristics of grout yield stress and viscosity in grouting region were analyzed. Variation law of calm water resistance，fluid phase resistance and solid phase resistance in grouting diffusion process were acquired. Results show that：Relationship between shearing stress and shearing rate of C-S grout is in good agreement with Bingham rheological constitutive model. With cement to sodium silicate volume ratio increasing，starting and ending time of fluid-solid phase transition shorten significantly. Furthermore，peak value of yield stress and viscosity increase markedly. Contrast to test results，theoretical calculation error of injection pressure based on Bingham model with time-varying yield stress and viscosity，Bingham model with fixed yield stress and Newton model were 12.73%–19.62%，20.12%–29.44% and 21.84%–31.35% respectively. For calculation of rock fissure grouting diffusion process，Bingham model with time-varying yield stress and viscosity is the best model of the three models. In whole grouting process，fluid phase resistance increases rapidly and then decreases slowly. Solid phase resistance increases approximately linearly. C∶S volume ratio has little effect on proportion value of fluid phase resistance and solid phase resistance at ending moment of grouting process，with proportion value of fluid phase resistance and solid phase resistance are 81.7%–82.9% and 15.7%–17.3% respectively.

In practice，many slope projects usually present complex infiltration boundaries due to functional requirements. In this paper，a series of physical experiments about rainfall slopes with different infiltration scenarios (rainfall covering slope crest only，slope surface only，and both slope crest and surface) were carried out. DIC image technology was used to capture the initial micro deformations and macroscopic overall asymptotic displacements during the slope failure. The contour maps of shear zones and contact force-chains were extracted，and the failure mechanism of high permeable soil slopes under different infiltration scenarios was revealed by the CFD-DEM numerical simulation. The results show that the rainfall covered slope crest only is easy to cause the failure of the slope toe first，then spread upward along the slope surface，and finally lead to the overall slip failure with the failure pattern of wide at the top and narrow at the toe. It had longer stability period，while its failure had characteristic of suddenness. When the rainfall covered slope surface only，plastic deformation was prone to occur first near the slope crown and slope toe. As two deformation areas continuously expanded and connected，it triggered the retrogressive failure with longer period. Its failure pattern presented narrow at the top，narrow at the bottom，and wide in the middle. When the slope covered by the full-area rainfall，overall failure was prone to triggered directly with characteristics of suddenness and linearity. Its failure pattern presented wide on the top，wide on the bottom，and wide in the middle. The scenario of rainfall covered slope crest only had the largest failure distance and failure depth，followed by the rainfall covered both slope crest and surface，while the scenario of rainfall covered slope surface only had the smallest failure distance and failure depth. The scenario of rainfall covered slope crest only was more dangerous than scenario of rainfall covered slope surface only due to the shorter failure period and sudden failure. In addition，the phenomenon of force-chain arch is prone to form at the back edge of the slip surface after the slope failure，indicating that the slope has the ability of self-stability.

The surrounding rock stress will redistribution during the underground engineering excavation process. This will affect the strength of weakly cemented soft rock，leading to uneven and large deformation of the surrounding rock of the tunnel，and even causing safety hazards such as collapse and roof fall. In this study，similar weakly cemented soft rock samples were synthesized using a mixture of bentonite，aeolian sand，gypsum，and talcum powders. Then，the directional shear tests with different direction angle of major principal stress were conducted by using GDS SSHCA hollow cylinder torsional shear apparatus. The stress vs. strain curves，peak stress variations，and shear strength are investigated and explored the strength anisotropic characteristics of similar weak cemented soft rock induced by the direction of major principal stress. The results show that both axial compressive strain and shear strain simultaneously generated when 0°＜ ＜45°( is the angle between the major principal stress and the vertical direction). And the axial strain gradually decreases，while the shear strain gradually increases with the increases of ；If = 45°，shear strain predominated and accompanied with volume expansion phenomenon. The samples were subjected to tensile stress and torsional shear stress，which lead to the axial tension and shear strains when 45°＜ ＜90°. The peak shear stress ratio( )max increased with =30°，after which it decreased until  = 90°. The peak shear stress ratio is 0.81，which highlights the rock?s pronounced anisotropic behavior. Utilizing the above findings and assumed the envelope of( )max in the deviatoric plane follows elliptical shape. Then，the elliptical anisotropic strength criterion of weakly cemented soft rock under directional shear stress path was established to describe the anisotropic strength characteristic of weakly cemented soft rock. The ellipse major and minor axis parameters can be obtained by using triaxial and pure shear tests. The validity of this model is confirmed by the results of directed shear tests. This research provides a theoretical basis for controlling deformations and preventing disasters in the field of underground engineering.

In order to improve the damage constitutive model and parameter determination method of sandstone under true triaxial loading and unloading conditions，based on the true triaxial fluid-solid coupling test system，the sandstone loading and unloading tests are carried out under different intermediate principal stresses and different maximum principal stress loading rates in true triaxial，to analyze the deformation characteristics of sandstone under different stress paths，the gradual damage characteristics of sandstone at different phases，and strength characteristics. Choosing the applicable strength criterion under the conditions of true triaxial loading and unloading，a damage constitutive model that can effectively describe the process of stress cracking of sandstone is established. The results show that the cracking stress，damage stress and peak strength of sandstone specimens increase with the increase of intermediate principal stress and loading rate. Under the two types of stress paths，the double-shear uniform strength criterion can accurately describe the strength characteristics of sandstone. By transforming the double-shear uniform strength criterion into a suitable yield function form and considering the damage evolution characteristics of the specimens in different principal stress directions，a true triaxial damage constitutive model was established to compare and analyze the effects of model parameters on the strain hardening characteristics. The model analysis results match with the actual test stress-strain curves in different principal stress directions，and the fitting results are more stable. The model can accurately reflect the influence of sandstone microelement strength by the stress state，and better reflect the force rupture process of sandstone in different principal stress directions，which can provide better theoretical guidance for the actual rock engineering practice.

The water-rock interaction at micro-meso-macro interface is closely related to the catastrophic changes in red-bed soft rocks. The study of the correlation process and cross-cascade effect at micro-meso-macro interface of water-rock interaction is of great significance to reveal the catastrophic mechanisms of soft rocks under water reaction. At present，the research on soft rock softening mainly focuses on the external characteristics of the meso-macro interface and its cascade effect. The correlation properties and cross-scale cascade effect of micro-meso-macro interface in red-bed soft rocks are in the exploration stage and still need further improvement. To address this problem，in this study，the correlation process of water-face interaction within red-beds soft rock is established by the analysis of micro-scale chemical reaction，meso-scale physical properties and macro-scale mechanical action of interface reaction process during soft rock softening. Based on the energy flow theory and the concept of cascade，the cross-scale cascade effect during the failure process of soft rocks was analyzed. The results show that the correlation process of water-rock interface can be well explained by three factors as follow：the cation concentration of aqueous solution，proportion of pores outside the framework of soft rock particles as well as quality of soft rock disintegration. During the softening process of soft rock，the micro and macro cascade factors show a gradual increasing trend. The imperfect correlation process of water-rock interface and cross-scale problem of cascade effect during the process of soft rock softening was solved and the references for revealing the deep mechanism of soft rock softening was also provided.

In order to investigate the blastability of frozen rock in the cold region blasting project，SHPB impact tests were conducted on frozen sandstone with different moisture contents. In addition，combined with the energy distribution of columnar explosives，the characteristics of frozen sandstone impact and blasting rock -breaking energy dissipation characteristics were studied. Based on this，the unit consumption model of explosive in frozen sandstone blasting was proposed，and the numerical simulation method was used to further modify the model. The results show that：(1) as the moisture content increases，the degree of damage to the sandstone specimens gradually increases；at the same moisture content，the degree of damage to the frozen sandstone specimens is weaker than that of the normal temperature sandstone specimens. (2) As the moisture content increases，the dissipated energy of normal temperature and frozen sandstone specimens gradually decreases；at the same moisture content，the impact dissipated energy of the frozen sandstone is higher than that of the normal temperature. When the moisture content is 0w，0.25w，0.50w，0.75w and 1.00w，the increase of dissipated energy is about 21.6%，64.9%，80.3%，78.2%，and 83.3% respectively. (3) The fitting equation of unit explosive consumption and moisture content of sandstone is obtained by equivalent calculation of the impact rock breaking energy of sandstone and the blasting rock breaking energy of columnar emulsion explosive. (4) Based on the simulation results of blasting crater test，the cubic root similarity law was used to correct the unit explosive consumption and a modified unit explosive consumption model of sandstone blasting is obtained.

The assessment of deflection and voiding resulting from shield tunnelling on overlying pipelines is critical for safeguarding their structural integrity. A method for calculating such deflection and voiding during shield tunnel excavation，taking into account variations in stiffness between the pipeline?s overlying and underlying subgrades，was developed using a double-layer Winkler foundation model. Model tests verified its applicability. Conventional subgrade bearing theories for pipelines buried in sand were refined based on plate load tests，providing recommendations for stiffness and ultimate bearing capacity relevant to soil-pipeline interaction during shield tunnelling. Parameter analysis revealed that void width increases with pipeline flexural stiffness and tunneling ground loss，albeit at a decreasing rate. Significantly，under conditions of high ground loss or pipeline flexural stiffness，both the soil-pipeline elastic interaction theory and the single-layer foundation method，considering interface voiding，tend to overestimate pipeline deflection and bending moments. In contrast，the double-layer Winkler foundation method，incorporating interface voiding，delivers a more precise prediction of pipeline deflections.

The preparation of centrifugal model of soft clay foundation is both the prerequisite and foundation of the test，and at the same time，it is also a technical difficulty. In this paper，a centrifugal model preparation method for saturated soft clay is proposed based on the combination of layered pre-consolidation and centrifuge consolidation under conventional gravity conditions，the principle and steps of layered consolidation method are elaborated in detail，and the changes of pore pressure and vertical displacement in the process of consolidation are analyzed and compared with the theoretical calculations of compression amount. The results show that： for the layered pre-compression consolidation，the settlement rate of 0.2 mm/h and the dissipation rate of excess pore water pressure of 0.2 kPa/h can be taken as the conditions for the consolidation and stabilization of the soft clay model when applying each level of loading；for the centrifuge consolidation，the model achieves the consolidation and stabilization state when the centrifugal acceleration reaches the target value of 5 hours，and the dissipation of the excess pore water pressure of up to 2 kPa/h and the surface vertical settlement up to 0.15 mm/h can be taken as the stabilization conditions for centrifugal consolidation of soft clay model. The research results and test steps can be used to provide methodological references and technical support for the preparation of soft clay centrifugal shaking table tests in the future，which is of scientific significance for improving the preparation accuracy of soft clay centrifugal models.

The shapes of natural sands often vary greatly. To study the characteristics of shear wave propagation in sand with different shapes，quartz sands with three different shapes were first selected for particle shape analysis. Secondly，a triaxial apparatus equipped with a bender element system was used to conduct shear wave tests and triaxial shear tests on sand samples，obtaining the shear wave velocities and critical state lines of the three types of quartz sands. The test results indicate that：(1) under similar void ratios and confining pressures，the shear wave velocity(Vs) of the quartz sands gradually increases as the overall regularity(OR) decreases；(2) based on the state parameter in the framework of the critical state soil mechanics，a new model that allows unified characterization of shear wave velocity for quartz sand was developed，and it shows a satisfactory predictive performance by using the data from the literature；(3) on the basis of the above model，a new method using the shear wave velocity was proposed to predict the shear response of quartz sands with different shapes. The outcomes from this study provide a basis for evaluating the shear instability of complex-shaped sandy soil layers using the in-situ shear wave velocity.