Both the determination and simulation of the sliding surface of slopes are the key problems in the stability analysis and design of slopes. The determination of the sliding surface is affected by many factors. The sliding surface of the heterogeneous rock slope needs to be investigated by the combination of geological and theoretical methods. At present，the commonly used simulation models of the sliding surface are the non-slip surface model，the thin layer solid element model and the interface element model. It was found out that the sliding mechanism for the instability processes of a landslide could not be simulated by the non-slip surface method. In the method of thin-layer solid element，the continuous deformation of rock mass elements is used to simulate the discontinuous deformation of structure surface. As to the joint element of Goodman，it is difficult to obtain the normal stiffness Kn and the tangential stiffness Ks，and the element embedding and overlapping are produced in the finite element analysis. Nevertheless，in the Katona internal interface element or the friction-contacting interface element，the strength parameters of joints or faults can be directly adopted without the need to determine the Kn，Ks parameters. Further more，the state of sliding，opening and closing of the contact surfaces can be well simulated with the friction-contacting interface element. The element type proposed was applied to a typical engineering case in order to verify the effectiveness of the method. The friction-contacting interface element was demonstrated to be reasonable by comparing with the results from field measurements.

In order to study the mechanical properties of sandstone，the conventional triaxial compression tests under different confining pressures were carried out on sandstone specimens. The test results indicate that the peak stress，the strain at peak point and the residual strength of sandstone increase gradually with the increase of the confining pressure. When the confining pressure is less than 15 MPa，the elastic modulus of sandstone increases with the increasing of confining pressure，but the rate of variation is smaller and smaller. When the confining pressure is larger than 15 MPa，the elastic modulus is independent of the confining pressure. The Duncan-Chang constitutive model was revised to describe the stress-strain response in the failure process of sandstone. The method of parameter determination was put forward based on the characteristic of the slop is 0 at the peak point of stress-strain curve. The triaxial compression test results of sandstone were used to evaluate the reasonability of the revised Duncan-Chang model. The comparison of predicted curves from the model and the test results shows that this model can accurately describe the strain softening property of sandstone and the other four stages of the failure process of sandstone under different confining pressures except for the closure stage of cracks. Especially，the model reflects the residual strength after sandstone failure. The further analysis on the model characteristics indicates that in addition to the strain softening property，the revised Duncan-Chang model can also simulate the strain hardening behavior of rock under the action of high confining pressure. So，this model has the good adaptability.

The self-weight stress and tectonic stress control the basic stress level of coal face，and the mining-induced stress caused by the moving of overlying strata contributes the most to the rock burst hazard. The multiple structures and movements of covering rock result in the complex mechanism and various types of rock and a burst. The relationship between the coal face boundary and overburden structure was studied，and a three-zone structure loading model was established. The influence of overlying rock structure on the stress field of rock burst was analyzed(mainly on the strike and dip abutment pressure induced by the movement of roof strata). According to the model，a monitoring and prevention method of rock burst was proposed. With the three-zone structure loading model，the type and grade and the risk of potential rock burst were classified.

Under the long term cyclic vibration loading，the primary structural plane in rock slopes may expand and produce new fracture surfaces，which directly affect the stability of rock slopes. According to the similarity theory，a physical model of a slope was built to simulate a jointed rock slope. The cyclic shear load was applied on the shaking table with the amplitude of 1.0，1.25 and 1.5 mm respectively and the dynamic response of the jointed rock slope under cyclic loads was recorded. The deformation of the jointed rock slope under the horizontal and vertical cyclic loads with the amplitude of 1.5 mm was compared. The deformation of the slope increases with the increasing of vibration amplitudes and vibration time. The slope is more sensitive to the vertical cyclic load，while the deformation at the top of the slope is larger than that at the bottom. The long term vibration load leads to the extension，expansion and coalescence of the primary crack，which increases the deformation of the slope. Two possible failure modes of the slope under cyclic loads，the integral landslide and the partial sliding，were presented according to the deformation results of tests.

Quasi-sandstone samples in dry and water-saturated states were tested in laboratory to analyze the non-isothermal heat transfer of rocks. The process of phase changes of water to ice leading to the reduction of heat conduction was investigated based on the experimental results. The equations of heat conduction in rock considering the effect of the cyclic freezing and thawing were proposed. The expressions describing the three-step change of temperature for the water-saturated rocks were also put forward and verified with the experiment results. The temperature variation curve of the dry quasi-sandstone samples under cyclic freezing and thawing changes negative exponentially. The rate of temperature change closer to the boundary surface is greater. The rate of temperature change in thawing period is greater than in freezing process. The temperature variation curves of saturated quasi-sandstone samples show three distinctive stages. The temperature changes slower during the process of phase change of water-ice. The rates of the temperature change of the saturated samples appear a bit lower than the dry ones. The structural transformation of water molecules during the process of phase change can be used to explain the phenomenon of reduction of thermal conductivity.

Temperature is one of the important factors influencing the physical properties of rock. In order to obtain the effect of temperature on the pore size distribution in rock material，the mercury intrusion porosimetry was adopted to test the pore characteristics of granite samples after high temperature treatment of 25 ℃–1 200 ℃. The fractal structure and model of pore size distribution under different high temperatures were then studied. The results showed that the rock porosity increased exponentially with the rising heating temperature and 500 ℃–800 ℃ was a threshold temperature interval. The porosity increased only 50% below 500 ℃ and about 3 to 5 times from 500 ℃ to 1 200 ℃. Most of the new pores and cracks induced by the high temperature are meso pores with the average diameter between 1 μm and 10 μm. The meso pores account for about 15% when the heat temperature is lower than 500 ℃，and then increases steadily and reaches 28.24% at 800 ℃，more than 40% over 1 000 ℃，and its volume increases by 11.8 times. The pore size distribution of rock under different temperatures exhibits a good statistical fractal feature with the pore fractal dimension between 2.99 and 3. With the rising of the temperature，the fractal dimension decreases more and more，which shows that the uniformity of pore distribution is raised. The model by ZHANG Jiru and TAO Gaoliang are proved better than the one of Friesen model based on ideal Menger sponge in predicting the rock porosity of different pore size.

The inclined long bolts for the crane beam being anchored in rock in the underground powerhouse are the important links of force transmission between the beam body and rock. A single bolt is divided into two parts: one section is surrounded by rock and another section is surrounded by the concrete of beam body. Based on the force characteristics of the bolt under the pullout load and the neutral point theory for bolts，the interactions of bolt，beam body and surrounding rock under the self-weight of beam，rock excavation load and the crane wheel were studied. A mechanical model of anchorage body including the asphalt was established. A new algorithm to calculate the forces of bolts was proposed，which is suitable for the stability analysis of crane beam anchored in rock. The numerical simulation on the force of crane beam anchored in rock during the construction and running periods was carried out with the 3D elasto-plastic nonlinear finite element method. The results of numerical simulation can reasonably reflect the stress characteristics of long bolts，and the calculated stresses in the bolts are in good agreement with the monitored values.

In order to obtain the optimal probability distribution of geotechnical parameters，the non-negative characteristics of the parameter values was firstly considered and an integral distribution interval standard was determined，which was based on the“ ”principle and adjusted according to the skewness of sample data. The probability distribution functions of five groups of typical geotechnical parameters were inferred by using the typical distribution fitting method(TDF method)，the maximum entropy method(ME method)，the general polynomial approximation method(GP method)，the orthogonal polynomial approximation method(OP method) and the normal information diffusion method(NID method). The Kolmogorov-Smirov testing method was used to assess the availability of those methods above. The availability of the probability distribution functions obtained with five methods were compared according to the testing values，the cumulative probability and the fitting function curves. The results show that the test values of four methods are generally lower than that of TDF method. And those four methods can overcome the shortcomings of the distribution with a single peak, reflect the fluctuation of the actual data distribution and meet the conditions that the cumulative value of probability is equal to 1. However，the test value of ME method is sometimes larger than that of TDF method，and the value of PDF at local distribution interval of distribution data will be less than zero for GP and OP methods. In contrast，the test value of NID method is the lowest and the cumulative probability value is always 1，and the fitting accuracy is the highest among all those methods. Finally，the criterion for judging the optimal probability distribution of geotechnical parameters is given.

To investigate the creep properties of in-situ glauberite salt rock during the process of solution mining，the mutifunctional rock testing machine was used to conduct the tri-axial creep tests under the confining pressure of 4 MPa，the axial pressure of 5 MPa and the infiltration pressure of 3，2 and 1 MPa，respectively. To simulate the processes of solution mining，the creep process of glauberite salt rock was divided into four stages including the creep stage of hydraulic connection(CSHC)，the creep stage with pore water pressure(CSPWP)，the creep stage after drainage (CSAD) and the creep stage under axial pressure of 20 MPa(CSAP). The creep behaviors of four stages were compared. The results show that the hydraulic connection time for galuberite salt rock increases with decreasing infiltration pressure. At CSHC and CSPWP，continual dissolution of the minerals and the effective stress have signifacant effect on the creep deformations of specimens. The deformations of glauberite salt rock at CSAD and CSAP are dominated by the loading history of dissolution and the softening degree of mechanical properties of solid skeleton. Finally，the generalized Kelvin model was used to fit the creep curves at different creep stages，and it can describe the triaxial creep behavior of glauberite salt rock under coupled effect of dissolution and infiltration pressure.

Current bolting theories without considering the dowel effect fail to reveal the mechanism of jointed rock bolts. In this paper，the mechanical characteristics of jointed rock bolts were discussed，and the transverse section of shear deformation of a jointed rock bolt was considered as a beam to establish the structural mechanical model. The load and deformation compatibility relationships of the transverse shear length were deduced. Based on the structural mechanics and the principle of minimum potential energy，an analytical model of jointed rock bolts was developed and an algorithm for calculating the transverse shear length on one side of the joint plane was proposed. It is revealed that the resistance of a jointed rock bolt is provided by the combination of the axial and shear forces，which act at the intersection of the bolt and joint. The resistance obeys a parabolic relationship. The larger the bolting angle，the greater the dowel effect. With increasing the bolting angle，the transverse shear length increases，but the resistance of the bolt decreases. Comparisons between the developed model and the experimental data were performed. It is shown that the proposed method agrees well with the experimental data and is thus proved to be reasonable and reliable.

There are three failure modes of landslides，that is，retrogressive landslide，thrust-type landslide and complex landslide. Different failure modes need different reinforcement measures. According to the definition of the point safety factor，the point safety factor along the slip surface can be calculated. The failure mode can be quantitatively described based on the distribution of the safety factor along the slip surface and the suitable reinforcement measures can thus be suggested. The calculated results of three classical landslides show that the failure characteristics can be well explained by the point safety factor along the slip surface. Finally，this method is applied in a large deposit located in the west of China. The engineering geological structure and the failure mechanism of the multi-layer deposit and the stability of the slope were preliminary analyzed based on the field survey and the effective reinforcements were suggested.

The evolution of microscopic fabric of rock has an important effect on its mechanical property and failure shape and it is therefore essential to study the microscopic fabric on rock. In this study，the scanning electron microscope(SEM) was used to scan the micro structure of the failure section of samples after compression shear test and Brazil split test. The morphological characteristics of the fracture surface of specimen were highlighted and the criteria of microscopic morphology matching macroscopic mechanical properties of crack surface were established. Meanwhile，the whole failure section of manufactured pre-crack was scanned with different angles of inclination. The criteria was applied to distinguish their microscopic morphology. As a result，the ratio of tensile-shear stresses on the fracture surface was obtained. The variation of the ratio in the cracking propagation process was studied. The results show that the ratio of tensile-shear stresses is closely related to the dip angle of the pre-existing crack. When the inclination angle is less than 45°，the tensile stress on the fracture surface is high，and the ratio decreases with the crack angle increasing. When the inclination angle is more than 45°，the results are opposite to the former. When the inclination angle is 45°，there are two macroscopic cracks owing to the combined effect of tensile and shear stresses. The proportion of wing cracks tensile stress changes from high to low during crack propagation process，and the results of secondary crack are converse to the former.

A seepage model test system for mining tunnel during construction and operation period has been used to predict the water inflow of a tunnel without considering the influence of excavation disturbance. The test conditions include the different permeability coefficient of grouting circle and initial lining. The numerical analysis was carried out with the Visual-modflow. The results from experiment and numerical analysis are basically consistent. The average value of water inflow is nonlinearly decreased with the decreasing of the permeability coefficient of the grouting circle and the initial lining，and the variance of single test value in each condition is also gradually reduced. The effect of reducing the permeability coefficient of grouting circle on the water inflow is more obvious. When the permeability coefficient of grouting circle was changed，the continuous collection of water inflow in each condition decreased first and then increased gradually to a stable value. And when the permeability coefficient of the initial lining was changed，the water inflow showed the trend of the gradually decreasing until it reached a balance. Non-disturbed excavation makes the groundwater to flow towards the tunnel which leads to the notable increase of hydraulic gradient around tunnel. The distribution of isopiestic line is dense and presents a concave shape in the direction of tunnel excavation. The well-functioning of the waterproof system(primary lining and grouting circle) played a significant role in maintaining the stability of groundwater. It effectively reduced the local hydraulic connection，reduced the influence of the seepage. The lowering of groundwater table was also significantly reduced.

The Newmark sliding block method was generally employed to calculate the seismic displacement of slopes. The calculation procedure considers only the parameters of the initial sliding moment，while the variation of the parameters due to the sliding rotation is not taken into account. Based on the theory of limit analysis，the influences of the sliding rotation angle on all the work rate and geometrical parameters are taken into account. The expressions of the real-time yielding acceleration factor，angular acceleration，seismic horizontal displacements are derived. Besides，a program was developed using Matlab software to update real-timely the dynamic parameters of the sliding soil mass in each sampling time-interval of the seismic wave and to realize the real-time dynamic Newmark sliding block method. This method was applied in a typical slope case and compared with the traditional Newmark sliding block method. The comparison indicated that the real-time yielding acceleration factor increased with the rotation angle increasing. The displacement considering the real-time dynamic effect was smaller than that from the traditional Newmark method，and the difference between them decreased as the global stability of slope increased.

Studying the change of meso-structure of rock during freezing has great significance for deepening the understanding of the mechanical and damage characteristics of frozen rock. The CT images of the meso-structure of rock at different freezing temperature gradients were obtained. The edge of CT images of frozen rock was detected using the Canny operator and two-dimentional meso-structure of rock during freezing was identificated. The composition and relationship of the meso-structure for frozen rock were analyzed based on the theory of stereo vision. The formula for calculating the characteristic parameters of meso-structure of frozen rock were presented. The variation of lengths，widths，areas and roundness for the pores and cracks were analyzed quantitatively during the process of freezing. The length，width and area of cracks (pores) were found to be rapidly increased in the temperature range of 0 ℃ to －2 ℃ due to the volume expansion of freezing water in the macroscopic cracks. The expansion rate of cracks (pores) was significantly reduced in the temperature range of －2 ℃ to －5 ℃. In this stage, It is deduced that the freezing process of the water in the meso-cracks (pores) (or partly micro) occurred. The expansion of the cracks (pores) increased again in the temperature range of －5 ℃ to －20 ℃，but with a lower rate than in temperature range of 0 ℃ to －2 ℃. In this stage the water in the micro cracks(pores) was transformed into the ice crystals.

Slate is a heterogeneous and continuous-discontinuous material filled with micro-fractures，pores，fabrics，etc.，and shows anisotropy in geological behavior，fluid flow and heat transfer. The slate samples from the auxiliary tunnel of Jinping hydro power station were cracked with an artificial diamond saw blade of ultrathin. The failure of samples under the uniaxial compression was observed with the 3D X-ray computed tomography system which is applicable to rock and soil. The difference between the sample failures with the loading direction perpendicular to and parallel to the bedding plane was obtained and the damage evolution of slate was also discussed on the meso-scale.

In order to study the deterioration of shear strength of sandstones，specimens were tested through UCS and TCS after different wetting and drying cycles in the environment of different pH values. The cohesion and internal friction angle were calculated，and the relation among the cohesion，internal friction angle and number of cycles was determined and the relationship between the shear strength and the number of cycles in acid and alkali environment was obtained. According to the mineral compositions of sandstone and their contents，the chemical reaction equations of the main mineral in neutral，alkaline，acidic solutions were obtained. The stability of the minerals in the neutral，alkaline and acidic solution was therefore interpreted based on the basic principle of chemical thermodynamics. In order to verify the correctness of the analysis，the concentrations of some ions(Ca2+，SiO2，Na+，K+) in the soaking solution were measured. The results show that the deterioration of the shear strength sandstones is most serious in the acidic environment，secondly in the alkaline environment，and least in the neutral condition. The main compositions of cement，calcite and feldspar，which have a great influence on the shear strength，are unstable in the acid environment because the dissolution reaction occurred spontaneously. The quartz，the main composition of aggregate having little influence on shear strength，is unstable in the alkaline environment with the dissolution reaction occurred spontaneously. The measured concentration of Ca2+，Na+，K+，dissolved from calcite，sodium feldspar，potassium feldspar in acid solution，were significantly higher than that in the neutral and alkaline solution，while the measured concentration of SiO2，dissolved from quartz in the alkaline solution，was significantly higher than that in the neutral and acid solution，which are consistent with the result from the thermodynamic analysis.

A sharp increase in the size of underground structures brings a great challenge to the anti-floatation design. A conventional passive method usually means a huge cost in finance and time. An efficient active method was thus proposed. The essential idea of the method is to reduce the water pressure by drainage and to control its environmental impact by cut-off walls(curtains). The application of the method in a practical case was addressed in details with the emphasis on how to make the drainage system reliable and maintainable. The drainage system has been on service over seven years successfully. It was found that a large diameter relief well made of pervious concrete was not clogged and easy maintainable. A stratum with a strong permeable soil layer is a favorable condition for the proposed method because the environmental impact can be controlled easily. In this case，the method should be first choosed.

The surrounding rock of the huge caverns of Baihetan hydropower plant is under the complex geological conditions and high in-situ stresses. The high stresses，shear zones and unloading induced spalling of brittle basalt，deformation and relaxation of columnar basalt in the process of the excavation respectively，which are the focus of this paper. The uniaxial compression and acoustic emission experiments were conducted in lab for the study of the stress induced spalling problem and the initiation criteria of crack strength of brittle rock was defined. The Hoek-Brown model using FLAC3D was applied to analyze the potential high stress concentration，and the supporting measure for the zones with damage risk under high stresses was suggested. For the local collapse，deep-seated deformation and shear displacement induced by the weak shear zones located at the roof or the high wall，the Coulomb-slip model using 3DEC for shear zones was employed in analysis with the feedback results from displacement monitoring. The reinforcement measures and ranges were determined. The columnar jointed basalt is discontinuous and exhibits the anisotropy in deformation and strength. The Comba model developed and the monitoring results with the field sonic wave were adopted to capture the anisotropic relaxation depth of the rock under excavation，which provided the helpful insights to the support parameters for design.

The slopes of open-pit mine are always in freezing- thawing environment in permafrost region，and the surface rock of slopes is weathering during the freezing- thawing cycles. The cyclic freezing-thawing tests on the saturated sandstone from the mining area in Muli were completed in laboratory in order to understand the physical and mechanical characteristics of saturated rock in freezing-thawing cycles. The degradation model for the saturated rock was studied. The micro-fracture rate increases gradually with increasing the freezing-thawing cycles，but the uniaxial and triaxial compression strengthes and other physical parameters decreases with the number of the freezing-thawing cycles. The micro-fracture propagation factor was suggested according to the micro-fracture change in the freezing-thawing cycles. The theoretical damage model and constitutive relations of rock strength were established using the micro-fracture propagation factor. The proposed model explained quantitatively the damage of the saturated rock due to freezing-thawing. The theoretical strength calculated with the damage model matched well with the test results. The composite stress generated due to water transformation to ice exceeded the strength of rock and drove the micro- fracture to expand.

Mudstone is a kind of soft rocks containing abundant clay minerals. The physical and mechanical properties change drastically when mudstone encounters water. Studies on the green and red mudstones from Tianshui，Gansu province were carried out. The experiment results show that the green mudstone contains more clay，while the red one has more primary minerals. The main clay mineral in both types of mudstones is illite，and there are less kaolinite and little montmorillonite. When the two kinds of mudstones interact with water，a lot of Na+，K+， but little Ca2+ are dissolved out. As a result，the thickness of the bound water membrane increases，the attraction between the electrically charged molecules decreases，the adhesion force diminishes and the minerals are much easier to be eroded. The results also indicate that under the condition of high water content，shear strength parameters of both mudstones change with the variation of water content and dry density，but the shear strength of green mudstone is better than the red. When the water content increases to 25%，the shear strength of red mudstone declines dramatically. And when the water content is over 30%，both type of mudstones almost lose the shear strength.

The method of approaching analytical solution to the elastic stress field of an infinite plane containing a single hole was extended to containing multiple randomly distributed holes of convex shapes under the arbitrary loadings on inner boundaries. Based on the principle of stress superposition，the stress field of an infinite plane containing m holes was divided into m stress fields，each with a single hole，referred as the isolated hole. A series of virtual tractions acted on the inner boundaries of holes. For one isolated hole，the virtual tractions generate the additional tractions on the inner boundaries of the other isolated holes. The additional tractions on one hole generated by all the other isolated holes plus the virtual tractions should be equal to the actual tractions acting on this hole. An iteration procedure was proposed to compute the values of virtual traction associated with all the isolated holes until the solution was converged. The elastic stress field within the infinite plane containing multiple holes is thus obtained. The results of examples show that the stress field of engineering scale obtained with this method agrees well with those from the finite element method. The values of stresses extremely near the holes can be computed as well and the generalized stress intensity factor and the order of stress singularity are obtained by data fitting.