The non-linear behavior of rock material in deep in-situ environment is very prominent. The existing rock mechanics theories are mostly based on the data analysis of ordinary cores obtained by drilling，which ignore the effects of in-situ environmental parameters (temperature，penetration pressure，etc.) at different depths and，hence，are no longer applicable to deep resource exploitation. A concept of coring with retaining in-situ conditions，including the pore pressure，temperature，quality，luminosity and humidity of original cores，is proposed，and the principle，technology and implement plan of coring with retaining in-situ conditions of deep rocks are developed. Based on the Steinmetz solid geometric principle，a self-triggered pressure control technology of deep rocks with a capacity of maintaining 100 MPa pressure of key parts is proposed through numerical simulation and physical test. An active and passive combined temperature maintaining technology is developed for thermal insulation system，and the maintaining temperature ranges from －8.8 ℃ to 100.0 ℃ in laboratory. The principle and method of cross-linking sealing film are presented. The polymer barrier film is formed after the reaction between A and B liquids，which can retain the quality，luminosity and humidity of in-situ cores in laboratory. This research can provide support for learning physical and mechanical characteristics for deep in-situ rocks at different depths，constructing new rock mechanical theory system，improving the deep resources exploration capability and exploring the mysteries of the deep earth.

Corrosion of steel bolts is a potential safety hazard in anchorage structure engineering. GFRP bolt has become one of the solutions because of its corrosion resistance and high strength. In order to study the durability of GFRP anchor structure，a stress relaxation experimental device for FRP anchor structure was developed，and three groups of experiments were performed to study the stress relaxation characteristics of pre-stressed GFRP anchor structure under the combination of corrosive environment and load. The evolution curves of stress and strain of the anchor structure were obtained and the effects of corrosive environment and load on the stress relaxation of pre-stressed GFRP anchor structure were analyzed. The results show that the developed experimental device can efficiently set up environmental impact conditions and capture the combination effect of corrosive environment and load conditions. The stress relaxation of GFRP anchor structure is affected by the environment and the stress，and the environment has greater influence. Most of the stress relaxation occurs in the early stage after loading. Stress relaxation of GFRP anchor structure mainly comes from bond degradation of the anchorage section，and partly from elastic modulus decrease of the bolt body. Compared with alkaline environment，the degradation rate of interface bond state of anchorage section in distilled water environment is higher. It is difficult to ensure the synchronization of deformation of GFRP bar and grating sensor by bonding coupling under long-term solution corrosion.

The hydraulic fracturing volumetric opening，which is defined as the volumetric opening in a per unit bulk volume of rocks，including pore volumetric opening and fracture volumetric opening，is an important reference in assessment of hydraulic fracturing effects. In order to establish a volumetric opening model combining the pore volumetric opening and fracture volumetric opening，in this study，a three staged evolving process model is proposed. Based on which，and using the theory of poroelasticity and a cohesive damage evolution model，a three staged expression of hydraulic volumetric openings is established. By matching the evolving law of fracture volumetric opening with the evolving law of the hydraulic fracture aperture，the fracture propagation regimes are incorporated into the hydraulic volumetric models. The main contribution of this volumetric opening model is bridging the gap between the two classic theories，poroelasticity and hydraulic fracturing propagation，by incorporating the parallel-plates-fracture into the hydraulic opening networks of micro cracks and pores. As examples，assessment of hydraulic fracturing volumetric openings in four limiting propagation regimes，are performed.

Brittle failure is an important mechanical behavior of rocks，and hence，it is of great significance to establish an accurate brittle evaluation method for rock engineering. Due to that the evolution characteristics of the elastic energy stored in rock before the peak directly determine the property of brittle failure after the peak，in this paper，a brittleness evaluation index based on the whole process of elastic energy evolution was proposed by comprehensively considering the characteristics of pre-peak elastic energy accumulating and post-peak elastic energy releasing. The brittleness evaluation index was used to evaluate the brittleness characteristics of different rocks under uniaxial compression，conventional triaxial compression and hydrostatic pressure conditions. The results show that the brittleness evaluation index established in this paper can fully reflect the brittleness characteristics of rocks. This index can accurately evaluate the difference of brittle characteristics of all kinds of rocks under the condition of uniaxial compression. The accumulating rate of the pre-peak elastic energy and the dissipating rate of the post-peak elastic energy of marble and quartz sandstone decrease with increasing of the confining pressure under the condition of conventional triaxial compression. It is also shown that the brittleness index of quartz sandstone increases with increasing the water pressure and the influence of the water pressure on brittleness index decreases gradually with rising the confining pressure. The rationality of the index was verified by the experimental results. The research work enriches the evaluation method of rock brittleness.

In order to study the fracture mechanisms of black shale with bedding and prefabricated cracks，Brazilian splitting tests were carried out on pre-cracked disk specimens，and the fracture processes of specimens were monitored by using a high-speed camera and an acoustic emission monitoring system. The results show that the prefabricated cracks can weaken the strength of specimens and the strength of specimens shows significant difference with changing the inclination angles of the bedding and the prefabricated crack. The position of the crack initiation point and the crack initiation angle are also affected by the inclination angles of the bedding and the prefabricated crack. When the prefabricated crack inclination angle is small，the crack initiation point deviates from the prefabricated crack tip and the crack propagates along the middle or the bedding surface of specimens. With increasing the prefabricated crack angle，the crack initiation point gradually transfers to the prefabricated crack tip and the crack propagates from the prefabricated crack tip to the loading direction. Moreover，the effect of the bedding inclination angle on the crack initiation angle decreases gradually with increasing  the prefabricated crack inclination angle. According to the morphology and generation mechanism of cracks，the failure mode can be divided into five types and temporal distribution of acoustic emission count can be divided into two types. By combining the results of numerical simulation and theoretical analysis，it can be seen that the black shale shows certain transverse isotropic characteristics，that the bedding effect increases with increasing the bedding inclination angle and decreases with rising the prefabricated crack angle，and that the maximum tangential stress criterion can be used as the criterion for the initiation of prefabricated cracks.

In order to solve the problem of large deformation of deep soft rock roadways，a kilometer deep roadway in Kouzidong coal mine was taken as the engineering example and the deformation mechanism of surrounding rock of the roadway supported by constant resistance and large deformation(CRLD) anchor cables was studied by means of theoretical analysis and physical model test. Firstly，the semi-circular arch roadway with straight walls was simplified into a circular roadway，and the distribution characteristics of surrounding rock stress and the analytical solution of roadway displacement under constant support force but different stress conditions were obtained based on the theory of elastic mechanics. Secondly，the roadway support experiment with constant resistance anchor cables was designed and carried out based on the similarity theory. The results show that the displacement of the roadway increases with increasing the surrounding rock stress and that，with rising the horizontal tectonic stress，the deformation on both sides of the roadway is gradually larger than that on the roof and the floor，indicating that the tectonic stress has a significant impact on the stability. It is also revealed that the CRLD cable can transfer stresses to the elastic zone，so that the rock mass of the anchorage zone plays a supporting role. The theoretical calculation values of roadway surrounding rock displacement are compared with the monitoring data in the model experiment，and a good agreement is obtained. Comparisons of the roadway deformation between the field monitoring and experimental results also give a good consistence with less than 5% of the surface displacement error of the roadway，which indicates that the model test has certain reference value.

In order to reveal the evolution of crack propagation and penetration in brittle solids under the action of ultrasonic field，the 3D-ILC method is introduced to ultrasonic fracturing tests for the first time，with different excitation durations and ultrasonic powers. The ultrasonic fracturing mechanism was revealed by analyzing the characteristics of fracture surfaces. The crack propagation path under different ultrasonic parameters was obtained through numerical simulation based on the Paris fatigue model and compared with the experimental results. The results show that 3D-ILC method is a powerful tool for ultrasonic fracturing research. Under the action of ultrasonic filed，cracks propagate along the tip，and the fracture surface shows the characteristics of shellfish veins and has powder locally. It can be judged that the ultrasonic fracturing mechanism includes ultra-high cycle/high cycle fatigue fracture，friction and temperature load. Ultrasonic action on solids is concentrated on original pre-cracked surfaces and no damage occurs in the intact region，which indicates that the ultrasonic action has “crack priority”. The area of crack propagation is positively correlated with the ultrasonic action time and ultrasonic power. Numerical simulation using the Paris fatigue model reveals that crack propagation is proportional to load amplitude and cycle number and that the crack propagation path is consistent with the test results. 3D-ILC provides a new means for the experimental and theoretical research of ultrasonic fracturing. Compared to traditional numerical methods based on the analysis of stress-strain and plastic zone，adopting numerical simulation to obtain the crack path under ultrasonic fracturing provides a good complement.

The visco-elastic dynamic constitutive relation is introduced into the Flat-Joint model based on the discrete element method，and a visco-elastic force-displacement formula and a rate-dependent broken criterion of contacts are derived. The rate-dependent force-displacement relationship and bond strength of contacts between particles are obtained. A subroutine(DLL) which could be called by PFC2D is generated with C++ based on the deduced formulas. By simulating the dynamic compression of rocks under different strain rates，relationships between the stress-strain curve，the quantity change curve of broken contacts and the distribution of broken strain of contacts with the strain rate are obtained，and the effects of the strain rate on the generation and distribution of cracks are analyzed. At the same time，the effects of visco-elastic parameters on the macro-parameters such as stress-strain curves and Poisson¢s rate，and deformation and failure characteristics of specimens are also analyzed. It is shown that the larger the elastic coefficient of elastic mediumis，the stronger the principal shear crack is，and the smaller the elastic coefficient of Maxwell mediumis，the more the shear cracks and dispersive cracks are. The viscous damping coefficient of Maxwell mediumhas little effect on the principle shear cracks，but the secondary cracks extending from the principal shear cracks increase with decreasing .

Based on the comprehensive analysis of the geostress characteristics，rockburst process and characteristics of the Kamchik tunnel known as the longest tunnel in Central Asia，a mechanical model of rockbursts is established，and an advanced support technology for active rockburst controlling is proposed. The study shows that，due to that the maximum principal stress of the geostress in the tunnel site is horizontal and close to the tunnel axis and that the tangential stress of the vault is maximal after tunnel excavation，rockbursts mainly occur near the vault in the Kamchik tunnel. The process of the rockburst can be divided into three stages including splitting of the vault rock，brittle fracturing of rock slabs and block ejecting. The mechanics model of rockbursts can be simplified as brittle fracture instability of a bedded rock plate of the vault under horizontal forces. The critical horizontal stress scr of the brittle fracture instability of the rock plate is inversely proportional to the square of the unsupported length L of the rock plate but proportional to the square of the thickness t of the rock plate. The mechanical model can well explain the occurrence and main performance characteristics of rockbursts in Kamchik tunnel. On this basis，an advanced support technology by reducing the unsupported length of the vault slab and increasing the thickness of the rock slab to increase the critical stress of brittle fracture instability，was developed for active preventing and weakening rockbursts. Applications of the technology in Kamchik tunnel indicate that the effect is remarkable.

Discontinuous structural weak planes are widely distributed in coal and rock，which causes that stress-strain curves under uniaxial compression show multiple stress drops. In order to explore the intrinsic mechanisms of intermittent failure of coal with discontinuous weak planes under loading，uniaxial loading tests were carried out on coal samples with dense fractures obtained from Tashan coal mine，Datong，and acoustic emission(AE) signals of coal samples were monitored in real time. The intermittent failure behaviors of coal samples were analyzed from the points of energy evolution，acoustic emission characteristics and failure morphology，and verified by a developed numerical model of particle flow code (PFC). The results show that the elastic deformation energy，showing a similar evolution trend to the stress-strain curve，reaches the maximum at the peak strength and releases completely after failure，and that the energy dissipation increases sharply when the stress drops suddenly and is equal to the total input energy after failure. There is a good correspondence between AE events and the stress-strain curve. When the stress rises steadily，there are fewer AE events，and most of them are low-level events. When the stress drops suddenly，a large number of high-level AE events cluster. Both AE b-value and fractal dimension D，reflecting the scale distribution and orderliness of micro-fractures，oscillate violently before approaching failure，which indicates that different scale cracks appear alternately in coal samples and adjust repeatedly from disorder to order，and there are many intermittent local failures before losing the bearing capacity completely. The numerical calculation shows that the tension crack first occurs at the tip of the primary cracks. When the stress drops suddenly，the number of bond between particles and cracks increase sharply，and the micro-cracks connect with each other to form large-scale cracks or propagate rapidly to the surface of the specimen. Local failure at different spatial locations causes zigzag of stress-strain curves at the pre-peak stage. Large-scale cracks cut specimens into independent bearing structures and destroy the bearing structure of the specimens，which is the internal cause of strength deterioration of the specimens.

In order to study the variations of the deformation and internal force under frost heave effect of lattice beam and anchor composite structure in cold regions，a calculation model of the composite structure considering frost heave is established basing on Winkler elastic foundation beam theory. Considering coordinated deformation of the soil and the support structure and regarding the frost heave displacement of soil as the superposition of free frost heave and constrained frost heave，a calculation expression of frost heave force is given，and calculation formulas of deformation and internal force of lattice beam under frost heave effect are derived by using the finite difference method. An example is illustrated，and it is shown that the displacement and internal force of the compound structure is very significant while considering frost heave effect，which indicates that the frost heaving force should be considered and enough safety margin should be set aside for the design of permafrost slope supporting projects. Comparisons between the model test results and the theoretical calculation show that the values of displacement and internal force of the lattice beam and the anchor tension are basically consistent as well as their variation trends，which indicates that the calculation method of frost heave effect is reasonable and feasible and provides a new idea for the analysis and design of the compound structure of lattice beam and anchor in frozen soil areas.

In the process of field geological exploration，geological engineers generally make a preliminary judgment on the lithology classification through the information of rock surface texture，color and hammering audios. Based on experts¢ experience and intelligent mode，a deep learning and intelligent recognition analysis method for rock lithology classification is proposed by using coupled rock images and hammering audios. Firstly，the Transfer learning method based on Inception-V3 is used to carry out deep learning and training on collected 6 types of rock images. Then，measuring the rock strength indicated as the average value of the rebound index by a rebounder and obtaining hammering audio segments by the threshold method，an SVM (Support Vector Machine) regression model of waveform and intensity is established to predict the rock surface strength. Finally，rock classification is intelligently recognized by coupling rock images recognition model with rock audio intensity regression model. The accuracy of rock classification is increased from 83.5%(only using simple images recognition model) to 90.5%. The coupling model can not only effectively identify rock lithology classification but also preliminarily give the rock surface strength，which provides a new auxiliary method for field engineering geological survey and is beneficial to improve the working efficiency of initial field exploration.

岩柱的间隔断裂(或岩芯饼化)是由拉应力导致的岩石破坏现象。通过将该类现象统一归结为岩石的自持续断裂，从理论上分析该类现象的发生机制；建立量纲一的饼化厚度d/D与量纲一的初始应力s0/st之间的关系式，且对表达式中各参数的物理意义进行了理论上的解释；并结合已有研究中的实测数据对所求表达式的适用性进行了初步检验。结果表明，当圆柱形花岗岩试样的初始应力为花岗岩抗拉强度的6.85倍及以上时，以一定的速率对岩柱轴向进行卸荷，将导致岩柱内产生与卸荷方向相反的断裂波和与卸荷方向垂直的断裂面；断裂波的波长与饼化厚度直接相关，初始应力越高、卸荷速率越快，断裂波的波长越短、饼化厚度也越小；断裂波随传播而衰减，由于沿岩柱轴向短距离内断裂波的波长变化并不明显，从而造成了饼化厚度在一定范围内依然看似相等的现象。从理论上讲，只要知道了岩柱的初始应力和残余应力，便可直接算出产生饼化现象的量纲一的应力阈值，而如何测量残余应力则有待进一步的研究。

Microseismic monitoring，as an indicator to determine the additional damage of rock mass，has been widely used in the identification，delineation and stability evaluation of surrounding damage areas during underground engineering construction. However，how to use the abundant microseismic information to calibrate the mechanical parameters of the rock mass is the key to quantitatively evaluate the damage degree and stability of surrounding rock. Taking Huanggou pumped storage power station as the research background，which is the first pumped storage power station to adopt microseismic monitoring for rockburst，microseismic activity and surrounding rock damage of underground caverns during construction are firstly analyzed. Secondly，a rock mass deterioration model using microseismic apparent volume to determine rock mass damage scale and considering cumulative damage effect is established. Finally，the FISH language is written to embed microseismic data into numerical simulation，and the stability analysis of surrounding rock of underground caverns considering cumulative microseismic damage effect is realized for the first time. The results show that the surrounding rock stability analysis method considering the  cumulative microseismic damage effect makes effective use of microseismic information reflecting abnormal activation such as external construction disturbance and geological structure，and that the analysis results of rock damage degree，stress field and plastic zone are in good agreement with microseismic monitoring results. The research work has guiding significance for optimal design of support scheme.

The small strain stiffness and Poisson's ratio of soils，closely related to the degree of saturation of the soil，play a key role on predicting the structure deformation caused by the interaction between soil and structure on the shallow surface. Adopting the experimental instrumentation developed independently，experimental investigations on soil cakes were conducted to explore the dependencies of the small strain stiffness and Poisson's ratio of fine-grained soils on the evolution of degree of saturation which is induced by adjusting environmental humidity under zero external load. The experimental results show that evolution of both the elastic wave velocity and small strain stiffness of fine-grained soils with the degree of saturation can be identified three characteristic stages including boundary effect stage，transition stage and residual stage. With decreasing the degree of saturation，the compression wave velocity and bulk modulus first decrease and then increase，the shear wave velocity and shear modulus increase，while the Poisson's ratio of the clay decreases linearly. In contrast，the Poisson¢s ratio of the silty clay changes limitedly and keeps in the value of 0.37 when the degree of saturation is lower than 85%. It is shown that the degree of saturation plays a more important role on the change of the small strain stiffness and Poisson¢s ratio of clay than on that of silts.

The adfreezing strength of the interface between soil and structure is an important parameter for the calculation of the tangential frost-heave forces and the establishment of the anti-freeze model in cold regions. In order to explain the formation mechanism of the adfreezing strength of soil-structure interfaces and to explore its influencing factors and changing rules，orthogonal direct shear tests were carried out under various conditions of moisture content，temperature and dry density. The test results show that the order of the influencing factors on the shear strength is moisture content，temperature and dry density and that the interface shear strength test is the best under the condition of low temperature，high water content and low dry density. The moisture content and temperature have significant interactive influence on the interface shear strength. The interface shear strength increases with rising the moisture content and the absolute value of the temperature. With increasing the normal pressure，the effect of the moisture content on the interface shear strength decreases gradually，while the effect of the temperature can still be promoted. Based on the experimental results，an explanation is given for the adfreezing strength formation and failure mechanisms of the interface between soil and structure. The research results can provide reference for the calculation of tangential frost-heave forces and the establishment of anti-freeze model.

The principal of effective stress is the foundation of soil mechanics. In this paper，two typical methods are used to analyze the inner stress of anisotropic soils in order to characterize the inhomogeneity of the internal stress and anisotropic mechanical behaviors of soil caused by the irregular shape and distribution of soil particles. The results show that，for anisotropic soils，the effective stress without considering the contact area of soil particles cannot describe the nonuniformity of the internal stress while the skeleton stress as a real stress can do. For ease of application，and referring to the physical connotation of the effective stress，an equivalent stress tensor is proposed to characterize the skeleton stress produced by all other external forces except for pore water pressure. The specific expression of the equivalent stress tensor is given with the fabric tensor，and the two-to-two conversion relations among effective stress，skeleton stress and equivalent stress are established. Moreover，using the equivalent stress to describe the soil skeleton stress and adopting existing constitutive model to simulate mechanical behaviors of soil skeleton，constitutive models of isotropic soils can be “anisotropized” without additional modification of the basic mechanical law of soils to realize the expansion of the principal of effective stress to anisotropic soils. Finally，as an example，the Lade¢s failure criterion is transformed into the equivalent Lade¢s failure criterion. Comparison with the existing experimental results proves that the expanded principle of effective stress is applicable to anisotropic geomaterials.

A new pile-plank subgrade configuration was employed for the modern tram track project in Shanghai. Since the tram track is embedded in road pavements and the subgrade configuration is quite different from that of the existing urban roads，the long-term lateral differential settlement between the tram infrastructure and the road infrastructure is an inherent issue. To investigate the lateral differential settlement distribution between the tram infrastructure and the road infrastructure，which are considered as a comprehensive research object in this study，some centrifugal model tests in different cases were undertaken，and the influence of soil stress history，track location and load distribution on the subgrade lateral differential settlement was investigated. Test results show that the soil stress history plays a significant role in effecting differential settlement distributions. The settlement of the tram foundation develops most rapidly in the initial 6 months of the operation，and then，the settlement rate decreases gradually with the operation time. The settlement of foundation soil decreases with the depth and the settlement influence depth beneath the pile bottom is about 4 m. Basically，the most serious case of the lateral settlement appears when the tram track locates by the side of the urban road. The maximum lateral differential settlement rate in the transition zone between tram and road infrastructures is up to 4.37‰，and the value of the tram system is up to 2.42‰. Consequently，some transition zone reinforcements are required.

To study the breakage and migration of soil and rock granular materials from the aspect of grain group，a series of one-dimensional compression tests with different vertical stresses and particle size distributions (PSD) were carried out on dyed gypsum particles. Particles of different groups were separated according to their sizes and colors by combining artificial recognition and image recognition software，and the particle breakage and migration mode，the particle breakage percentage and the breakage overlap effect were analyzed. It is found that particles undergo more than one generation of breakage with broken particles migrating from bigger size intervals to the adjacent smaller ones，and thus，the PSDs of each-color particles are ungapped. With decreasing the particle size，the particle breakage percentage of the better-graded particles increases(for samples with a relatively narrow PSD) or increases first and then decreases(for samples with a relatively wide PSD)，but is lower than that of the uniformly graded particles in general. The breakage overlap is described as the phenomenon that the mass of survived particles within a size interval decreases obviously after crushing while the overall mass of the size interval drops little or even increases. In addition，an absolute particle breakage index considering breakage overlap is established based on the concept of grading entropy. The test results can also provide a reference for the numerical simulation of particle breakage.