There is rich hydroelectric resource in Southwest China with high mountains and deep canyons，and many hydropower projects with high dams and large reservoirs are located in this area. Due to specific topographic and geological condition，stability of the complex high slopes in these projects has become one of the key technical problems which restrict the effective development of hydroelectric resource and project construction. Taking the hydropower project practice in Southwest China into consideration and combining the corresponding research achievements，main technical features and key problems of slope engineering have been summarized and analyzed，and research approaches and contents of rock engineering has been brought forward. On this basis，some new ideas and methods such as genesis of deep fissures in slope，slope structure，parameter values，safety criterion，reinforcement design method，feedback analysis，etc. have been put forward from several aspects including geological condition，slope engineering design theory，and construction process controlling，etc. These methods and theories have been successfully applied in the design and construction of slopes in hydropower projects. Particularly，the extremely high slopes in Jinping I project(530 m) and Dagangshan project(420 m) consisting of deep unloading and relaxation rock masses have been successfully constructed. These research achievements bear beneficial reference significance to the investigation and design of slope engineering and the development of rock mechanics.

Jinping I Hydropower Station located in the Southwest China is a key cascade and control underground hydropower project at the Yalong River. The project is very huge and the underground powerhouse system is very complicated，as well as the complex geological conditions，lower strength for rock relative to very high geostress especially. The challenge which no found in historical projects is presented by two dominate aspects in the construction. The two ones are stability and reinforce of surrounding rock. The characteristics of deformation split of surrounding rock and failure of supporting structure is described based on the geological conditions，monitor and geophysical prospecting，investigations in-situ and tests data. The correlations are discussed which deformation failure of surrounding rock and supporting structure with geostress，rock mass structure and mechanical property of rock under loading and unloading. The geomechanics mechanism of deformation failure of the surrounding rock and supporting structure is explained. The tangential loading stress is rather large and inclined to split pressed at downstream side(especially hance) of main powerhouse and main transformer house，but the normal unloading stress is rather larger and inclined to tension and relaxation unloaded because of the high geostress and its direction. The rheological behaviour of the fracture surrounding rock is presented，and is gradually charactered from surface to deep，the time-dependent deformation of fracture rock mass with surrounding rock relaxation is showed. The surrounding rock at downstream side is easy to bend and break-off and low susceptibility to shear and slide of main powerhouse and main transformer house under secondary stress field，because that the upstream side is bedding but the downstream inverse slope with low dip angles. The powerhouse marble is presented that relative lower strength，heavy brittle and lower strain strength，easy to tension pressed under unloading.

Due to the heterogeneity of rocks and the complex environment around rock mass，rock mass always presents anisotropic creep behavior in the loading process. In order to describe the anisotropic creep behavior of rocks，a viscoplastic fluidity parameter tensor is proposed；and the anisotropic visco-elastoplastic creep model of fractured rock is developed. The rock matrix and fracture are represented by introducing statistical distribution and weak element，respectively. A cellular automaton creep updating rule is established. This model is integrated into the EPCA3D and a numerical system EPCA3D-EVP to simulate the creep failure process of heterogeneous rocks is compiled in VC++ environment. The model and numerical method are validated against creep tests of fractured granite，which comes from the nuclear waste underground disposal candidate site in Beishan，Gansu province，China，with consideration of hydro-mechanical coupling effect. It is found that，larger lateral creep deformation of fractured granite under the effect of seepage，compared with the situation in dry condition. The EPCA3D-EVP system is used to simulate the creep test process. It is found that the simulated results are in well agreement with experiments，indicating that the developed model can well reflect the anisotropic creep phenomenon of fractured granite under the hydro-mechanical environment. The developed model can be used to long-term stability analysis of rock mass under complex conditions.

Taking the San-I No. 1 tunnel damaged by the 1999 Chi-Chi earthquake for example，the associated failure mechanism is studied by means of numerical analysis and related investigation results. Numerical simulation results reveal that，in accordance with all depths of damage sections close to 0.25 wavelengths of incident waves；the combination of tunnel depth and wavelength causes wave reflection from ground surface and wave scattering from tunnel periphery，and leads to particularly pronounced amplification of earthquake-induced stress of lining，that results in lining damages. The four significant damage patterns of lining are also elucidated，including the longitudinal cracks，circumferential cracks or construction joint dislocation，circularity-spalling of lining concrete，as well as oblique cracks and associated spalling of lining concrete. The earthquake-induced exceeding axial-and flexural stresses caused by the S wave with vertical and 45? incident angle yield to the longitudinal cracks. The tensile failure caused by horizontally propagating P wave and the stress increment caused by Love wave dominate the circumferential cracks or construction joint dislocation. The stress increment caused by the S waves with 45? incident angle，occurred nearby opening refuges and amplified while a tunnel subjected to significantly horizontal stress results in the circularity-like spalling. The propagating S wave induced distinct strains in-between of the soft and hard rock layer lead to the oblique cracks and associated spalling. This study clarifies the earthquake-induced damage patterns of rock tunnels and associated affecting factors，which is conductive to aseismic design for tunnels.

The deformation characteristics of surrounding rock after excavating and supporting of coal roadway with great-thick mudstone roof，its failure mechanism and its controlling countermeasures are systematically researched through field investigation，laboratory test，numerical testing，similar simulation and theoretical analysis. Meanwhile these methods are used to represent dynamically the process of rock deformation and failure in the roadways，and the roadway?s behaviors including deformation characteristics，failure mechanisms，stress distribution in the surrounding rocks and the effects of various support systems on roadway stability are studied. Some conclusions can be drawn as follows：(1) The fracture，cracking and separating layer of the thick mudstone roof occurred and promoted promote by two ways，such as the weathering，disintegrating，disruption，dilatancy of the mudstone，as well as the concentrated tensile stress and shear stress in the stress adjustment. (2) Based on the study，it is shown that the original supports in the absence of accurate judgment of the surrounding rock result in the roadway destruction and the supports system abated. (3) The principles to support the mudstone roof are enclosing in time，enhancing the stiffness of the lower rock layer of the roof and disposing the anchor cables along the cracks. (4) Based on the geological mechanics and environmental conditions of the roadway surrounding rock，an optimized roadway support design is provided that effectively avoid the multiple recondition by changing the cross-section and modulating the support parameters. The long-term stability of the thick mudstone roof had been realized. After several successful engineering practices，research results have been adopted in Qipanjing mining area；and the results have great theoretical and practical values to similar roadway supports.

Using self-made “triaxial stress thermal-hydro-mechanical coal containing gas permeameter”，an experimental study was carried out to investigate how the unloading speed of confining pressure influences the mechanical properties and gas permeability of containing-gas coal rock，under cooperation of different initial confining pressures and various gas pressures. The research result showed that from an aspect of mechanics，the coal would first undergo a stage of stress flat roof，after the unloading process began，and then a break would happen due to destabilization. When the confining pressure was unloaded at a higher speed，the destabilizing breakage was easier to happen on the coal which also represented shorter time to maintain at the stage of stress flat roof. During the unloading process of confining pressures，the time of coal being in the stage of stress flat roof showed a power function with the unloading speed of confining pressures. From an aspect of gas permeation，the permeability of coal was tightly relevant with its deformation and the changing trend of its volume strain could well reflect the changing trend of its permeability. When the confining stress was being unloaded，the permeability of coal varied in an experience of four stages and it kept increasing. The permeability of coal increased at a faster rate when the unloading speed was larger. During the unloading process of confining pressures，the permeability of coal being in the stage of stress flat roof showed an exponential function with the corresponding time.

Through bore in the top rock and laneway，the bore-laneway observing system is formed. According to mining velocity，the changing characters of electric field in different time can be tested；and the changing law of overburden failure affected by mining can be analyzed comprehensively. The height of “two belts” gained by detection is helpful for safety production of mine. Using the practical coal seam as the geological model，the mining condition of coal seam is found through the technique of the similar simulation. The detection simulation is arranged combined with the bore-laneway resistivity system. The comprehensive analysis result can improve the accuracy for the height of the “two belts”. The research results of simulation show that the bore-laneway resistivity method has sensitive reaction to structure change affected by mining. The resistivity ratio section of several time and background detection can resolve effectively the characters of stress excess，distortion and failure of rock during the process of the model mining. According to the detecting results in model workface，the height of caving zone is 0.07 m；and the height of failure zone is 0.33 m. According to the proportional similarity of 100，the result is consistent with the practical measured values in mine workface.

Testing system MTS 815 is used to carry out uniaxial and triaxial compression tests for Qianjiaying rock，coal and coal-rock combined body，and their mechanical behaviors and failure modes under different stresses conditions are obtained correspondingly. The similarities and differences between them are analyzed in detail. The shear failure，splitting failure and mixed failure are the main failure modes for Qianjiaying sandstone under uniaxial condition. In addition，the peak strength and modulus of sandstone are similar proportional relationship with wave velocity. Under a certain conditions，such as the circumferential displacement control loading，high strength and low non-homogeneity of rock，type II failure curve of rock can be obtained. However，type II failure can not take place in coal or coal-rock combined body. Under uniaxial compression condition，splitting failure is the main failure mechanism for coal sample. However，the relationship between the peak strength，elastic modulus and wave velocity is not obvious. Under different confining pressures，the failure of coal-rock combined body mainly occurs in coal body. Under uniaxial condition，the failure mechanism of coal-rock combined body is mainly splitting failure. In addition，the high velocity crack propagation in coal body can induce the damage of rock；and the cracks in coal can extend to the rock. All of these can lead to the failure and loss of bearing capacity of coal-rock combined body. However，under triaxial compression condition，the failure mechanism of combined body is mainly shear failure；and the combined body after failure have residual strength. With the increase in confining pressure，the elastic modulus of Qianjiaying combined body increases slowly at the beginning and then increases quickly when the confining pressure is larger than 15 MPa. The peak strength of combined body is approximately linear with the confining pressure.

The lagging water-inrush near mine fault belt is the main type of water damage threatening the deep coal mining. Based on the flow-solid coupling theory，three types of simulation model including the elasticplastic strain-seepage coupling model，the rheology-seepage coupling model and the variable parameter rheology-seepage coupling model were proposed. Regarding the materials of fault zone as equivalent continuum model，using elasticplastic model and rheological model as material constitutive model respectively，a numerical simulation was carried by using FLAC3D. The results show that the simulation of the elasticplastic strain-seepage coupling can be applied to some circumstances；the rheology-seepage coupling is the closest to reality；under the condition of the variable permeability，the variable parameter rheology-seepage coupling gives the best explanation to the mechanism of permeability parameters changing. Taking the rheology-seepage coupling model for example，the most dangerous time occurring possible lagging water-inrush can be identified better. In the three mining stages simulated，the highest water pressures of 3.26，3.63，3.77 MPa are generated separately near rock roadway，i.e.，at the location of model observation point #8，corresponding to lag times of 15，131，546 d respectively.

On the basis of strip mining characteristics，the exchanging technology of gangue backfill was  described briefly firstly according to subject of strata movement and quadratic stability of coal-pillar under three circumstances exchanged by gangue backfill，mining process of coal-pillar. Mechanism and characteristics of quadratic strata movement were also analyzed. It is considered that the main mechanism is compression of the gangue filling support body and bearing rock strata，and curving belt of overlying strata show the wavy type sinking curved layer. Then，some analytic formulae of the bearing body of“bearing rock strata + gangue filling support body”were deduced by means of the elastoplastic theory and based on the actual force and ultimate strength of the gangue filling support body，these analytic formulae includes the quadratic stability condition，the safety factor，the width of plastic area under limit state and the width of bearing core area. Calculation formulae of the compression amount of gangue filling support body(w1) and the quadratic compression amount of bearing rock strata(w2) were got；and the sinking total amount calculation method of quadratic strata movement was put forward too. Theoretical calculation results of Baoyuan Coal Mine indicate that the safety factor of the bearing body of “bearing rock strata + gangue filling support body”Fs = 1.36，and placed in stable state. The sinking total amount w is 0.833 m，the bearing bodies resist against high stress，and maintain quadratic stable of overlying strata. Numerical analysis results show that there is a saddle distribution for above vertical stress of the gangue filling support body；the average value of maximum subsidence displacements of bearing rock strata is about 0.801m，which closes to the theoretical value.

This paper reports friction experiments performed on samples collected from the earthquake-hit region of the Longmenshan fault zone(LFZ). The materials tested consisted of simulated gouges prepared from intact clay-rich mudstone and sandstone，a calcite limestone，and a natural fault gouge from a trenched， surface rupture cutting the mudstone and sandstone. The clay-rich samples， including the natural fault gouge，were dominated by illite and quartz. In the experiments，1 mm thick gouge layers were sheared between saw-cut driver blocks，using a triaxial testing machine at conditions corresponding to 2 km depth in the LFZ. Temperature was varied from 25 ℃ to 150 ℃ and，to investigate the velocity dependence of friction，the shear displacement rate between 1.22 and 0.122 ?m/s was stepped. The results show that the natural fault gouge was more illite-rich and much weaker than the protolith mudstone and sandstone，and showed a steady-state friction coefficient of 0.4 compared with 0.6 for the latter. The limestone fault gouge displayed values of 0.6–0.7. All samples，except the limestone，showed stable，velocity-strengthening slip. The limestone showed velocity-strengthening at 25 ℃－50 ℃，but quasi-static oscillations at 100 ℃－150 ℃ along with velocity-weakening behavior at 150 ℃. The result is applied to discuss the role of the sedimentary rocks studied during events such as the Wenchuan earthquake；and it is argued that the clay-rich sediments of the region may have a damping effect upon ruptures propagating from depth；whereas the limestone may accelerate propagation，producing significant stress drops.

Based on the results of rock triaxial test，the creep mechanical properties of the sandstone from the compressive rupture zone in Xiangjiaba Hydropower Station are investigated，and the laws of axial and lateral creep of rock are also analyzed. In the low stress level，the rock only appears decay creep and steady creep. The steady creep strain rate is non-zero constant，and the creep deformation cannot be ignored. The creep of rock is consistent with Burgers model. When the stress reaches a certain level，the accelerated creep damage of rock occurred after the decay creep and steady creep. The characteristics of rock creep failure under different confining pressures are different，especially the starting time of accelerated creep. According to the feature，the startup component of accelerated creep is proposed. By connecting the startup component and Burgers model in series，a new six-component nonlinear viscoelasto-plastic creep model of rock is constructed. The creep property of the nonlinear model is carried out based on the theoretical analysis. The creep constitutive equation in three- dimensional stress state is deduced. The creep parameter identification method is investigated. The comparison between nonlinear creep model and experimental curve shows that the proposed nonlinear viscoelasto-plastic creep model is available and reasonable.

On the view of energy，energy absorption and release of the deformation and damage process of sandstone are studied under cyclic loading of pore water pressure. The results show that plastic-loop is divided into four stages during a single cycle；and energy absorption and release is also divided into four stages. In loading，energy absorption per unit volume and energy release per unit volume decrease and gradually tend to stabilization with the increase number of cycles and the greater lower limit of pore water pressure，the greater energy absorption per unit volume and energy release per unit volume are. Axial effective stress of demarcation points of energy absorption and release increases with the increase number of cycles. In unloading，energy release per unit volume decrease with the increase number of cycles；while energy absorption per unit volume increase with the increase number of cycles and the greater lower limit of pore water pressure，the smaller energy absorption per unit volume is. Axial effective stress of demarcation points decreases with the increase number of cycles. Plastic energy per unit volume decreases with the increase number of cycles which means that the deformation and damage of rock decreases under a single cycle of rock pore water pressure. At the early stage of the loop，the greater lower limit of pore water pressure is，the smaller plastic energy per unit volume is.

The diversion tunnel for Jinping II Hydropower Station is currently the largest group of hydropower tunnels in China. The surrounding rock masses of the tunnel are of long length，deep embedded depth and technical difficulties of construction，which is a variety of geological hazards such as water bursting，rockburst，collapse and so on. It is necessary to choose the safe and rapid excavation technology for ensuring construction safety and power generation schedule，so a large number of studies and analysis of the technology of TBM construction is conducted；and the results are as follows：TBM construction method is feasible not only in the view of rock drillability and cutter wear but also from rock deformation and fracture；but it is some advantage for the traditional drill and blast method to deal with issues such as groundwater，rockburst，large deformation and so on，and which has a better protective effect in the personnel safety. It can do better in solving a series of engineering problems on the construction process if using the continuous improvement of construction technology and supporting tools which come from between geological prediction and construction.

The joint orientation is a crucial factor which influences the penetration rate of TBM tunneling. Based on laboratory test，the effect of joint orientation on the penetration under TBM disc cutter is studied. In the test，two kinds of concrete with different strengths are adopted to simulate rock sample. The angle ? between joint plane and tunneling axis varies from 0°，30°，and 60° to 90°. The main conclusions can be drawn as follows：(1) chipping angle ? increases with the increment of angle ? from 0° to 60°，and is about 33°－50° when ? = 90°which agrees with the Hertzian cone crack. The angle Δ? between side crack and joint plane is about 40°－70° whereas ? changes from 0° to 90°. The angle Δ? between median crack and joint plane is about 0°－10° as ?≤30°，and arises sharply when ?≥60° which makes median crack joints with joint plane to cause chipping. (2) The test results show three possible chipping modes of rock fragmentation：first，the side crack initiates beneath the crushed zone and propagates to free surface or joint plane to produce chipping. Second，the median crack propagates downwards to the joint plane to produce chipping as ?≥60°. Third，the crack initiates from the joint plane due to joint deformation and propagates to the free surface when ?≥30°. (3) The penetration rate achieves the highest value at ? = 60° and joint gives more notable effect on fragmentation of the rock with higher strength.

The fatigue damage of granite under cyclic fatigue load are caused by the propagation and coalescent of cracks at mesoscale，so it is of important theoretical value and practical significance to understand the fatigue properties of rock by experimental research on meso fatigue damage of granite. The whole test scheme included two parts as follows：the uniaxial different frequencies cyclic loading and unloading tests and the meso-damage quantification tests based on SEM. The uniaxial different frequencies cyclic loading and unloading tests on granite were done on the RMT–150B multi-function automatic rigid rock servo material testing machine. Sine wave cyclic loads with stress amplitude of 10 MPa and seven different frequencies of 0.01，0.02，0.05，0.10，0.20，0.50 and 1.00 Hz were adopted as dynamic disturbance. A great deal of mesostructural images of granite has been obtained by means of scanning electron microscope(SEM). It is shown that when the cyclic frequency is relative low，intergranular cracks are the main forms of meso fatigue damage of crystals. When the frequency is relatively high，intergranular cracks are the main forms of meso fatigue damage of quartz and mica crystal and the forms of meso fatigue damage of feldspar are intergranular cracks，transgranular cracks and grain cracks. The azimuth of intergranular cracks and grain cracks tends to the axial direction of cyclic load. But the azimuth of transgranular cracks appeares irregular. And the major meso fatigue damage is intragranular cracks.

The experiments of the deformation and failure of rock under the condition of uniaxial compression were carried out by using the white digital speckle correlation methods. According to the experimental data collected in different ways，the experiments were divided into two groups. A group of experiment investigated the deformation evolution process of rock loaded，the specimen surface speckles images were recorded by CCD camera，According to the calculation results，the rock deformation evolution was studied. The other group of experiment investigated the deformation evolution process of the transient of rock damage；the specimen surface speckles images were recorded by adopting high speed cameras. By adopting the different times speckle images as reference frame，the plastic hardening to peak stage deformation evolution characteristics and the peak to destroy phase analysis of deformation evolution characteristics were carried out. At the same time，some quantitative parameters were obtained in the experiments，such as the value of deformation，the ratio of maximum and minimum values of the deformation in the deformation localization band，the ratio of deformation values inside and outside the deformation localization band，and the average speed of crack propagation.

Based on the joint information from in-situ survey and numerical simulation technique of joint(Monte- Carlo method)，the Fish language in UDEC is adopted to compile a program to generate the calculation model of fractured rockmass named DFN-GEN. DFN-GEN program can solve the problem of discrete mesh caused by the various joints. With this program，lots of random joints are generated；the fractured rockmass is meshed directly and the calculation model of fractured rockmass is generated which is finally used in the hydro-mechanical(HM) coupling calculation. DFN-GEN program is adopted to generate the calculation model of fractured rockmass and to study the hydro-mechanical coupling behavior of rockmass. Combining with TASK C of the international cooperation project DECOVALEX，the discrete fracture network(DFN) is generated and the HM behavior of fractured rockmass is studied. The effect of stress on equivalent permeability of rockmass is also analyzed. A basis is provided for engineering practice of fractured rockmass such as underground disposal of nuclear waste repository，dam foundation，slope stability and so on.

Based on a series of plane strain cyclic tests on air-dried Toyoura sand，the viscous properties of sand under loading-unloading conditions are presented. Comparisons are made on the stress-strain relationships of two sets of tests using different strain loading rates. Creep stages are also performed during the tests. Special attentions are paid to the viscous behavior of sand during unloading. The tests reveal that the viscous behaviors of sand are deeply related to the strain loading rate as well as the stress level. The viscous behaviors of sand caused by the viscosity of loading will be weakened with the increased of load and strain. Furthermore it is found during the unloading test，the vertical strain of sand continues to grow for a certain period of time even when the unloading has already begun. The behavior of creep recovery is also observed during unloading. Based on the general framework of the three-component model，the temporary effects of strain rate and acceleration (TESRA) model is put forward and modified for the simulation of viscous behaviors of sand during loading-unloading. The detailed formulation and controlling parameter are presented，enabling the implementation of a reasonable numerical simulation. Applying this model，simulation is conducted on the primary loading-unloading stage of sand in the plane strain tests. The stress-strain relations as well as the time history of strain are obtained. Through comparisons between the results from test measurement and numerical simulation outputs，the TESRA model is proved both effective and precise for simulating the viscous behaviors of sand during loading-unloading.

The relative density Dr，which has a dramatic change before and after loading during construction，is a major factor for the strength-deformation property of sands. However，the effect of Dr was not taken into consideration in most elastoplastic models. To solve this problem，a new elastoplastic model，the SMP-Lade model，was established by considering the Lade-Duncan model and SMP criterion. Then，based on triaxial consolidated-drained tests data on ISO standard sands of China，the sensibility of the model parameter to Dr was analyzed. Furthermore，based on the disturbed state concept(DSC)，the general disturbance function(D) was established. The disturbance parameter could be deduced from the relative density of sands. At last，the elastoplastic model considering disturbance，which could reflect the contribution of disturbance to the strength-deformation property of sands，was proposed through establishing the relationship between parameters K and peak strength(κf －ft) and disturbed degree. Supposing that the material parameters χ and ψ and the parameters of the SMP-Lade model at initial state were given，the stress-strain-volume change relations of sands at randomly disturbed state could be predicted by the proposed model. The test results show that the proposed model can well describe the strength-strain-volume change relations of sands at a given disturbed state.

As a new type of inorganic reinforced material，potassium silicate(PS) can greatly improve the mechanical strength and the ability of anti-wind erosion of earthen ruins soil after being reinforced. Therefore，a test device for determining the thermal conductivity of ruins soil was developed. Then，soil specimens were made from the disturbed soil collected from site of Jiaohe Ruins；and then，in order to study the influence of PS on the heat transfer process of the soil，the determination test of the thermal conductivity and the laboratory model test were carried out. Test results show that the thermal conductivity of PS reinforced soil is reduced；furthermore，the larger the concentration of PS is，the smaller the thermal conductivity of soil is. In addition，it is found from the laboratory model test that when external temperature changed，the PS reinforced soil responded slower to the temperature change compared with that of the untreated soil；so，it is inferred that due to PS reduced the thermal conductivity of reinforced soil，and the heat transfer process of the soil is hindered. The finding above shows that PS reinforced soil can slow down the physical weathering caused by temperature difference；and this will have an important significance on studying the conservation of earthen ruins in Northwest China arid areas.

To study the rheological properties of subgrade compacted soil，three kinds of subgrade compacted soil?s traditional direct-shear and consolidation experiments as well as consolidation creep and shear-consolidation coupled creep experiments were carried out respectively by using improving experimental devices. Their basic mechanical properties and creep experimental data were obtained. Using these experimental data，similar Maxwell  rheological constitutive model of subgrade compacted soil was set up with three parameters，which was based on fractional calculus theory and Mittag-Leffler function；and its parameter was realized to automatic identification by introducing Deborah number，adopting area determinant function with weight and the manner of point-by-point searching. The results show that the established rheological constitutive model with a few of parameters fits the experimental data with accuracy；so it has a good application value.