The Jinping Underground Laboratory(CJPL) in China is currently the world?s deepest laboratory in overburden. The paper focuses on the second phase project of CJPL，namely CJPL–II. Rock mass behaviors during the whole excavation process were real-timely obtained via a comprehensive monitoring approach，including the measurement of deformation and fracturing of rock mass，the elastic wave testing，the distribution stress testing，the micro-seismic and AE monitoring，the 3D laser scanning，the rock mass structure photogrammetry，the rock blasting monitoring，etc. It was also achieved that the multi-scale ruptures，from micro to macro，of rock masses，as well as their deformations from excavation surface to deeper surrounding rock，were detected or monitored. Based on a proposed identification approach of the engineering geology，the geological zones of deep rock mass structure were distinguished，in which rock mass deformation characteristics and their failure modes as well as the deformation and fracturing information prior to rock mass hazards were revealed. Several tunnel hazards including rockbursts and collapses were pre-warned，which ensured the safety during the construction of tunnels. This research with lots of basic data obtained is great significant to safe construction and the long-term operation of CJPL-II and to explore the deep problems of rock mechanics and engineering science.

基于热力学势函数引入损伤理论，建立适用于深部岩体的新结构超塑性损伤本构框架。通过定义新内变量对：应变(损伤积累应变，结构重排应变)及相应广义应力、温度和熵，用4种热力学能量函数：内能，Helmholtz自由能，焓和Gibbs自由能描述岩石结构超塑性本构关系。本理论框架即能满足热力学定律具有严格物理意义又能对结构性进行较合理考虑。通过Legendre变换建立各能量形式间的转换。利用运动内变量参数及其共轭变量(广义应力)引出耗散势。给出承压变温条件下深部岩体的塑形耗散函数或屈服函数形式，可反映损伤并考虑结构重排的体变行为，两者通过Legendre变换的退化特例进行联系。构建适用深部岩体热力学本构理论框架下具体的应力–应变增量本征关系及其新应用实例，并提供应用性的判断依据。该理论对深部地下工程实践中岩石的力学分析具有借鉴意义。

Gas fracturing，as a new type of waterless fracturing technology，is important to the exploitation of shale gas. In order to explore the failure mechanism of shale with bedding planes of different directions due to the gas fracturing，the anisotropic mechanical properties of black shale from Pengshui were systematically analyzed. The gas fracturing tests on the axis of the shale samples parallel to and perpendicular to the direction of bedding plane were performed using the reformed assembly of high pressure gas fracturing system respectively. The effect of the directions of bedding plane on the deformation，strength，AE characteristic and failure modes was discussed and failure mechanism of shale was revealed. The effect of layer on the shale strength under different loading modes was discussed. The effect of bedding plane directions on the tension-compression properties of black shale is obvious. The ratios in compressive strength，tensile strength，elastic modulus and shear modulus of the samples with the axis vertical to bedding plane direction and the samples with the axis parallel to bedding plane direction are 138.22%，44.37%，169.17%，173.27%，respectively. However，the effect of bedding inclination on Poisson?s ratio of shale is not apparent. The failure strength and failure time of the samples with the axis vertical to bedding plane direction are 4.2 times and 3.35 times greater than the samples with the axis parallel to bedding plane direction respectively. The former appeared the tensile failure along a weaker bedding layer and the latter mainly produced the tensile failure，but the shear failure can be also found in the latter resulting in an uneven fracture surface. The deformation carves are nonlinear. The deformation of the samples with the axis vertical to bedding plane direction is larger，and the abnormal inflection point and down concave trend in the lateral deformation curves were shown clearly in this case. While for the samples with the axis parallel to bedding plane direction，the deformation curves are relatively smooth and the concave trend was shown in the lateral deformation curves. The samples with the axial vertical to bedding plane direction were failed more violently according to the results of AE energy rate. The loading modes affected the bedding effect coefficient of shale strength significantly，and the gas fracturing test affected the most and the uniaxial compression test affected the least.

In order to investigate the characteristics of ultrasonic wave velocity and acoustic emission activity of salt rock under triaxial loading，the multi-level cycle loading tests were conducted using a device composed with the acoustic wave and acoustic emission testing systems. The variations of ultrasonic wave velocity and AE number of salt rock were consistent with the loading stress. In the loading process，the ultrasonic wave velocity increased and AE activity was intense. However，there were opposite characteristics when the stress was unloading. The higher level the loading stress was，the more significant the feature was. The loading level of the confining pressure had great influence on the ultrasonic wave velocity and acoustic emission activity. The rate of change of the ultrasonic wave velocity was greater and the AE events were more under the lower confining pressure than when the confining pressure were in a higher loading level. This can be explained by the principles of confining pressure densification. In the paper，the unloading modulus，the fracture density and the ratio of Felicity were used respectively to express the damage evolution for salt rock. Results showed that the features of fracture density and the ratio of Felicity had a good consistency with the salt rock damage，which reflected the process of damage fracture well. Because of the plastic deformation，the unloading modulus was not suitable for describing the damage.

Because of the large size of the underground powerhouse of Baihetan hydropower station at left bank，the local failures of surrounding rock occurred frequently subjected to excavation. To study the mechanisms of rock deformation and failure subjected to unloading caused by excavation，an ESG(Engineering Seismology Group) monitoring system was applied to monitor the microfractures in real time during the excavation processes in the underground powerhouse. Microseismic(MS) activity was found to be in good agreement with the excavation. Three potential failure zones of the underground powerhouse under the first layer excavation were revealed，i.e.，the downstream spandrel between unit 4 and unit 5 of the main powerhouse，the upstream spandrel between unit 6 and unit 7 of the main powerhouse，and the crown above unit 8 of the main powerhouse to the crown of the transformer chamber. The moment magnitudes and Es/Ep of microseismic clusters controlled by the excavation strength and faults were very different，resulting in the different potential failure modes of surrounding rock. The targeted supports should be adopted in the MS clusters based on the evolutional MS characteristics. Several days before the local deformation of the surrounding rock，the area manifested with the accelerated cluster of MS events，quick increase of the apparent stress，but rare change of the cumulative apparent volume.

In order to investigate the variation of permeability during the gas drainage in coal seams，a model of variation of coal permeability was established based on the Kozeny-Carman equation，the theories of surface physical chemistry and effective stress of the coal containing gas. The effects of the effective stress，gas desorption and coal matrix shrinking were taken into account in the model and the permeability variation during the gas drainage in coal seams was analyzed using the numerical simulation method. The proposed model was found to describe effectively the variation of permeability during the gas drainage in coal seams. The relationship between the permeability and gas pressure displayed a“V”-shape trend of variation. The coal matrix shrinking was the dominant factor in the low gas pressure stage，and coal permeability increased with the decrease of gas pressure. The effective stress effect was the dominant factor in the high gas pressure stage，and coal permeability increased with the increase of gas pressure. If the distance between the specific point in coal body and the gas drainage hole wall decreased gradually，the coal permeability dropped firstly and then went up when gas pressure was relative high，and the coal permeability increased continuously when the gas pressure was relatively low.

Fluid-solid coupling models were established based on the unsaturated soil mechanics. The pore water pressure distribution and unsaturated soil strength were applied to the limit equilibrium method considering the soil-water characteristic curves and the seepage characteristics. Combined with the finite element method，the numerical computations to the seepage，the stability and the stress-strain with saturated and unsaturated properties under steady-transient conditions were carried out to Gongjiafang colluvial landslide under the action of reservoir water in Wuxia gorge section，Three-Gorges reservoir. The Seep module was used to simulate the influence of water on landslide and the change of underground water levels. The calculations of the limit equilibrium and stability of the fluid-solid coupling were carried out with Geostudio-slope. The Sigma software was applied to analyze the unsaturated-unsteady seepage，stresses and strains. The dissipation of the pore water pressure difference，the time effect of seepage line lagging behind the reservoir water and the space effects of the mutual impact between the moisture migration and soil deformation in the slope were revealed. The water in the slope played a role of jacking，wedging and actuation. The hydrops in the top tensile crack is disadvantage to slope stability. The leading edge of the slope was steady while the middle and latter edge played a role of pushing and controlled the overall stability，which reflected the protective effect of the anti-slide piles under the coupled action of seepage- stress.

With the increase of excavation depth，the zonal disintegration phenomenon in surrounding rock of deep cavern appears，which is quite different from the failure mode of shallow cavity. In order to further study the mechanism of zonal disintegration，an elastic damage softening model for zonal disintegration was put forward based on the strain gradient theory and continuum damage mechanics. The equilibrium equations and boundary conditions of quasi-plane strain problem were deduced considering the out-of-plane stress influence. The numerical solutions of radial displacement and radial strain and stresses in deep surrounding rockmass were calculated using Matlab. The numerical solutions presented an oscillation mode. The theoretical calculated values are in good agreement with the model test data. The applicability of elastic damage softening model for zonal disintegration in the explanation of zonal disintegration was confirmed. The oscillation mode of stress in deep surrounding rock is the critical reason for the formation of zonal disintegration.

In order to stduy the crack extension and mechanical characters of explosive blasting in different layers of coal-rock media and to increase the permeability of coal seam of low permeability in the deep hole pre-splitting blasting，a blasting simulation test system was set up in the laboratory. Two different charging modes of drilling borehole，cross and down the seam，were designed. Deep hole pre-splitting blasting test model was built based on Froude proportion method and the samples with the size of 50 cm×50 cm×50 cm were prepared with the similar materials. Under the above conditions，blasting simulation tests were carried out. The strain signals of coal rock were monitored with the super dynamic strain gauge. The whole process from the crack initiation，expansion and breaking through to the destruction of samples was recorded with the high speed camera. The dynamic mechanical and crack propagation properties under blasting loading were analyzed. The results showed that the cracks were mainly formed by the interaction of the compression and unloading waves and the direction of crack propagation was perpendicular to axis direction of hole. The effect of drilling blasting with borehole cross the seam was better than that down the seam. When the blasting stress wave was from the coal seam to the rock，the reflected tension shock wave was arisen to react on coal seam，which resulted in the aggravated damage of different coal-rock media and prompted blasting crack extension.

The method of calculating the geometric parameters of the three-dimensional passive failure elliptical cone of shallow tunnel face was improved through introducing the expression for the elliptical locus of the intersection between the cone and plane. The upper bound expression of the passive failure pressure on three-dimensional shallow tunnel face and the optimal upper bound solution of passive failure pressure were obtained based on the upper bound limit analysis and nonlinear failure criterion. Reliability of this method was verified by comparing with other results. The effect of non-linear shear strength parameters on pressure and failure modes was investigated. Besides，the figures of failure modes were drawn. The passive failure pressure changes basically linearly with the ground overload ?s and soil density ?，but changes nonlinearly with the nonlinear parameters m，dimensionless parameter c0/?t and critical pressure ratio C/D. The failure modes were found to depend significantly on the nonlinear parameters m，dimensionless parameter c0/?t and critical pressure ratio C/D，but the ground overload ?s had smaller effect on failure modes.

In order to solve the problem that CABLE element in FLAC3D cannot be broken failure，a broken criterion U(i)≥Umax(i) was proposed and a modified mechanical model of CABLE element was established. The broken failure function was added to the modified model and the new model was embedded in the main program of FLAC3D with the FISH language programming. The broken failure of bolt was realized at the single element level，and the macroscopic broken was finally achieved from parts to whole spontaneously. The tensile tests of bolt bar and the roadway bolt-shotcrete support tests were carried out. The load-displacement curve of the cable bar using the modified model presented the broken failure characteristic，which was in accordance with the actual mechanical behavior of bolt rod，and the quantitative broken effect was achieved and the response was sensitive. When the ground stress exceeded a certain value，the modified bolts and anchor cables broke in the surrounding rock，the mechanical behavior conformed to the broken failure mechanism of bolt or cable anchor in the practical engineering. The simulation accuracy was improved. The application range of FLAC3D was expanded，and the simulation capability was enhanced.

The microscopic geometrical characteristic of the surface sedimentary tailings is described in this paper. Microscopic experiment and theoretical analysis were used to research the microscopic geometric characteristics of tailings and the effect of distance on microscopic geometric characteristics. Some charts and indicators were used to describe the microscopic geometric characteristics，such as the number or area frequency distribution histogram of grain size，circularity，roundness and textural fractal dimension. Tailings grains according to their microscopic geometrical characteristics were divided into the micron-sized grains and the non-micron grains with the boundary of 35 ?m. The derived formula showed that the distribution of surface sedimentary tailings was affected by the grain size，initial flow velocity，gradient，etc. The stress ratio was 1.4 when tailings reached the critical state.

In order to study the spatial distribution and development of ground fissures，3D seismic exploration was carried out for the area with ground fissure outcroppings in Jinzhong Basin. Data was acquired by using shooting-off-end swath acquisition-geometry survey，processed by pre-stack time migration to improve the accuracy of the fissures space and the effect of image，and interpreted for ground fissures based on the seismic multi-attribute analysis，especially the ant-tracking technique. The total area of the studied district are 4 km2，and 20 ground fissures were interpreted with 11 principal ground fissures and 9 secondary ground fissures. Some of those ground fissures were interpreted as the outcrop on the surface，while some dip all the way down to the bedrock. The ground fissures are line-like distributed from plane view with a dominant orientation of NEE. In general，they have the same direction as the major faults in Jinzhong Basin and have the distinct structural direction. From the section view，the strata on both sides of ground fissures displaced to each other with a throw of 0–40 m. In 3D space，they are horsts and grabens. 4 out of 5 ground fissures that outcrop on the surface in the studied area were confirmed by this prospecting，which indicates that the 3D seismic prospecting is an effective approach in ground fissure detection.

Concrete-rockfill combination dam(CRC dam) is a new type of dams. The stability of the concrete wall and the whole dam was influenced by the value and distribution of earth pressure. A model test was carried out to measure the distribution of earth pressure along the height of the wall and to investigate the displacement mode in rock filling and water impoundment periods. According to the results of loading and unloading triaxial test，the non-linear relationships between the wall displacement and the mobilized internal friction angle，the friction angle between the concrete wall and the rockfill were established under the quasi-limit state. The concept of initial displacement was proposed，and a calculation method of quasi-limit state earth pressure considering the displacement was deduced. The result shows that the displacement of the concrete wall was mainly the mode of translation. Earth pressure varied with the displacement of the concrete wall obviously，and the earth pressure at the end of impoundment period was approximate twice than that in the filling period. The proposed formula reflected well the change of earth pressure with wall displacement and is an effective supplement to Coulomb?s theoretical formula.

Investigation of ground deformation at different mining levels of metal mines may offer the decisions of delineating the scope of the surface movement and subsidence and safe production. In situ monitoring data on ground surface and in deep underground in the west part of Chengchao iron mine over the period of 8 years were collected and the regular pattern of ground deformation under different mining level were analyzed. When mining the levels of －290，－307.5 and 325，the roof stratum entered its initial caving stage. When mining the level of －342.5，the roof stratum entered the stage of the large amount of caving intermittently. When mining the level－358，the ground deformation was continuous and the ground subsidence funnel broadened homogeneously. When mining the level －375，the surrounding rock mass entered the stage of rapid outward extension，the boundary and movement line of ground deformation extended largely，the ground subsidence funnel in the footwall broadened unevenly in January 2010，and the ground movement showed catastrophe. When mining the level －395，the surrounding rock entered the stage of a slow deformation，and the boundary line and moving line extended a little. The ground deformation was still very severe in the subsidence areas of the footwall and appeared no tendency of ceasing

Asymmetric deformation failure during the process of excavating and supporting of large cross-section entry roof with strong mining disturbance and fully-mechanized caving mining at Wangjialing coal mine was studied systematically through field investigation，laboratory test，analytical analysis，numerical simulation and in-sit test. The mechanism of deformation failure and the controlling measures were investigated. The roof of gob-side entry was found to display the asymmetric deformation failure characteristics，which included sever subsidence of roof near the pillar sides，radical horizontal dislocation deformation and dislocation，embedding，step convergence at the roof-wall corner，et al. The lateral main roof broke at a distance of 6–7 m away from the gob-edge above the pillar. Unbalanced side abutment q and rotary deformation pressure ? induced by the broken and rotation of main roof are the fundamental cause causing the asymmetric deformation failure characteristics. The deformation failure was significantly influenced by a key position of roof near the pillar side and roof-wall corner surrounding rocks. Due to the movement of the unstable overlying strata and the entry excavation，the surrounding rock structure and stress distribution were asymmetric evidently on the axis of roadway，but the original supporting systems did not provide the reinforced support to key position and adjust to the strongly horizontal dislocation，which resulted in the asymmetric strata behaviors shortly after the development of entry. The asymmetric failure tended to be more severe later affected by the extraction of the present panel. The control principle of the entry was analyzed and an asymmetric supporting system was proposed composed of cable- beam-net，asymmetric cable-beam and cable-truss. And the support scheme was put into field application. The numerical simulations and engineering applications demonstrated that the support weakened the asymmetric of stress and displacement of the roof and controlled the asymmetric deformation failure.

The X-ray diffraction(XRD)，the mercury intrusion porosimetry(MIP) and the environmental scanning electron microscope(SEM) were used to study the activity of fine aggregate of coal gangue under different calcination temperatures and the pore structure of hardened cement mortar of fine aggregate. The relationship between the pore structure and the strength of cement mortar was analyzed. The fine aggregates of coal gangue of different activity had the different levels of secondary hydration reaction with the hydration products of cement in the early period of hydration. The activity of fine aggregate of coal gangue affected the pore size distribution and porosity of hardened cement mortar. A highly active fine aggregate of coal gangue reduced the porosity of hardened cement mortar and optimized the pore size distribution. The harmful holes greater than 200 nm decreased significantly and the less harm or harmless holes of 100，20 nm increased. The hydration products of hardened cement mortar increased accordingly. The activity of calcined fine aggregate of coal gangue from low to high refined the porosity of the mortar，improved effectively the pore structure of cement mortar，reduced its porosity，and improved the strength of the mortar.

Fly ash filling materials at early age have low strength，large deformation，poor liquidity and severe water bleeding. Several experiments on the fly ash filling materials with three different mixing ratios at early age were carried out to study the bulk electrical resistivity，the electrical resistivity of pore solution，the uniaxial compressive strength and the elastic modulus varied with time . The porosity variation with time was analyzed with the initial porosity and measured 1 d porosity of the filling material. The bulk resistivity was found to increase-decrease-increase with time. The resistivity of pore solution decreased firstly then tended to a stable value. Both the bulk resistivity and the resistivity of pore solution were influenced by the dosage of fly ash. The uniaxial compressive strength and elastic modulus increased with the extending of the hydration time，but decreased with the increase of the dosage of fly ash. The porosity decreased inversely exponentially with the extending of hydration time and decreased firstly then increased with the dosage of fly ash. In the late age of hydration，both the uniaxial compressive strength and elastic modulus were related to bulk resistivity logarithmically. The hydration process at early age can be divided into four stages，such as adsorption period，a dissolution period，setting period and hardening period.

The stepped overloaded plants were needed to be built on a landslide slope for a tungsten mine. Four rows of anti-slide piles were proposed for the treatment of sliding mass as well as the foundation of intra-plant step retaining wall and plants. In this case，the dual function of load-bearing and anti-slide could be utilized for the load-bearing and anti-slide piles. The optimization design and treatment methods for landslide under stepped overloaded plants were presented. Based on the transmit-coefficient method，an approach of resistance distribution of multi-row load-bearing and anti-slide pile was proposed considering the upper plant loads. With this method，the distributions of multi-row piles at the tungsten ore plant were calculated，and then the optimized design of load-bearing and anti-slide piles were conducted. Finally，with the long-term monitoring data of the landslide and the calculation results from finite element method，the rationality of the proposed method for the resistance distribution of multi-row pile was validated，and the applicability of the optimized design method for landslide treatment was verified. According to the inadequacies of resistance distribution of multi-row load-bearing and anti-slide pile in the current specifications，corresponding supplementary suggestions were proposed in this paper.

The pile-sinking process in saturated clay is regarded similar as the cylindrical cavity expansion under undrained conditions. Considering the soil strength in three-dimensional stress state，the SMP criterion-based Cam-clay model was adopted to solve the cylindrical cavity expansion and to derive the general solution. On this basis，the fixed solution of spatial axisymmetric consolidation equation was built. A series solutions of the dissipation of excess pore water pressure were derived by using the methods of separation of variables. The development of excess pore water pressure around piles with time and space was discussed. It was revealed that the impact of the radial and vertical permeability coefficient，the stress history and the shear modulus on the initial excess pore water pressure and the rate of consolidation. The theoretical solution was proved reasonable and applicable in comparison with the measured data. The excess pore water pressure around piles decreases with the increase of logarithmic radical distance. Shear modulus and vertical permeability coefficient have little effect on the rate of consideration，but the radial permeability coefficient and over consolidation ratios has a significant effect on it，that reflects the dissipation mainly along the radial direction.

Three common excavation methods in centrifuge model tests were reviewed，including the excavation at 1 g，the drainage of appropriate liquid to simulate excavation and the excavation in-flight using a micro robot. A new excavation device was designed and developed on the basis of the understanding of the excavation processes. It was confirmed to be feasible in a centrifuge model test on foundation pit engineering in sand ground. Compared with the traditional methods，this method can be used to realize the excavation in-flight，to simulate more correctly the lateral earth pressure，and to simplify the excavation process. In the test，the multiple types of sensors were arranged to form a three-dimensional measurement. The test results were compared with the numerical simulations. It was found that the test results were always smaller than those from simulations. The surface settlement profile caused by excavations was a spandrel type. The position of the maximum induced bending moment of the retaining wall moved down along with excavations，but the moving rate decreased gradually. The upper excavation had little impact on the deep earth pressure. Similarly，the changes of the shallow earth pressure were not obvious when the lower soil was excavated.