Calibrating safety criteria by the First Order Second Moment Method is a standard approach specified in codes. EuroCode I refers it as the‘Level II approach’. This paper presents a criterion called‘Ratio of safety margin’that is used to assess the universal applicability of a calibrated safety criteria based on the target reliability index. Following a brief review of the theoretical background described in the existing codes，the author calibrated the equivalent factors of safety and partial factors based a target reliability index on a selected test example by the First Order Second Moment Method. The calibrated safety criterion was then examined by varying all the related geometrical and physical parameters of this selected example，making sure that the values of ?R，?F，and ?P are approximately same. Formulations have been given for defining the‘Ratio of safety margin’designated ? for reliability index，factors of safety，and partial factors with subscripts R，F，P respectively. Having passed this universal applicability test，the calibrated values have been promoted for practical application with more confidence. The author reviews its successful applications in the area of stability analysis for embankment dams，reinforced slopes，retaining walls，and concrete gravity and arch dams. The author summarizes the calibrated acceptable factors of safety and partial factors in these areas associated with the required reliability indices.

Due to the natural defects existing in rock mass，freezing-thawing damage is easier to occur around these defects. In fact，the freezing-thawing damage can be regarded as the fatigue process along the local area of the natural defects under the repeated frost loading. However，the significant scale effect exists in the freeze-thaw damage. The spatial scale of these defects always control the evaluation scale of freezing-thawing damage. For example，for the porous rocks with the defects such as cavity，porosity and micro-crack，their freezing-thawing damages commonly present the germination，extension and cutting-through of these porosities and micro-cracks，which can be classified in the microscopic scale. While for the fractured rocks with fault，joint or fracture，their damages show the typical localization characteristics along the tips of macro defects，which should be considered in the macroscopic scale. The scales of freezing-thawing damage and its corresponding damage recognitions are the focus of this work. Firstly，the quantitative grading are carried out according to the spatial sizes of these natural defects，and the damage characteristics and the corresponding recognition for different scales are also discussed. Then，the recognition and evaluation methods of freezing-thawing damage in the micro-scale，meso-scale and macro-scale are concluded comprehensively. Finally，combing with the present works of the evaluation of freeze-thaw damage of rock mass，we attempt to present the viewpoints regarding the future development of recognition methods and damage evaluation mechanism，and to discuss briefly the cross-scale evolution paths from micro，meso to macro scale in the freezing-thawing damage of rock mass.

The problems of hyper speed impact effect on the ground are pointed out in this paper regarding the penetration and ground impact effects of hyper speed projectile. The theory of elastic-plastic fluid and internal friction penetration was applied to study the hydrodynamic model，so as to expound the essential relationship and difference between the penetrations of hyper speed projectile and conventional ground penetrating bomb，and also to define the range of the speed of hyper speed penetration. It was found that with the increasing of penetration speed，the target medium was transformed from the elastic-plastic state to the internal friction state，then to the fluid dynamic state. The mechanical phenomena of hyper speed penetration characteristics were also presented，such as the penetration depth reversal due to the mass abrasion of projectile，and the penetration depth tending to the limit as a result of the projectile erosion. The methods to calculate the depth and crater range of hyper speed penetration were presented.

The schistosity plane of quartz-mica schist from Danba is well developed with typical anisotropic characteristics. In addition，the quartz vein in quartz-mica schist leads to more complicated anisotropic characteristics. First of all，the mesoscopic structure analysis was carried out on the rock chips in the small scale of indoor experiments，and a number of sets of tests with different loading directions to schistosity plane were carried out. The deformation modulus and the strength of quartz-mica schist were found to change with the schistosity angle. In the simulation with particle flow code(PFC)，the smooth joint was adopted to simulate schistosity plane and the rock matrix was simulated as particles. The method produced the failure process of schistosity surface and rock matrix and reproduced accurately the results of indoor test. In order to study the characteristics of the anisotropy of large scale rock mass，the rock mass structure，especially the spatial distribution characteristics of quartz vein were collected and counted by the three-dimensional digital camera technology. The characteristics were accurately reproduced in numerical modeling. The anisotropic characteristics of quartz-mica in different sizes and with different structures were studied.

The unique occurrence and mining scheme of steeply inclined coal seams have a great tendency to cause dynamic instability and analyzing the instability characteristics and influential factors of steeply inclined coal seams is critical for safe mining. A comprehensive methodology including in-situ investigation，theoretical analysis，numerical calculation，physical experiment and field monitoring was adopted to investigate the stability of rock surrounding roadway. The relevant results indicate that the deformation and failure of roof side behaves as the synthetic buckling towards the direction of free face，while the one of floor side behaves as the shearing slip. The initial deformation position locates in the middle of roof side roadway，while the one in the floor side locates on the bottom corner. The horizontal span of instability area in roof side and floor side reached approximately 2.1 m and 1.7 m separately，leading to the severe asymmetrical deformation. The physical modeling experiment shows that the acoustic emission(AE) and infrared(IR) thermal joint monitoring system provided the indicator information of surrounding rock failure of roadway. The maximum accumulative convergence reached 39.2 cm after optimized support scheme was applied，the deformation rate reduced about 82.2 percent of original deformation. So the effect of optimized support scheme is remarkable.

In order to investigate the influence of moisture content on the long-term stability of deep rock，the siltstone from －906 m of Zhujidong coalmine was studied. A series of uniaxial compressive creep tests of cyclic wetting and drying on the siltstone were carried out in stepped loading on the rock creep testing machine ZYSS2000 under high temperature and high pressure. The test results show that with increasing of wetting and drying cycles，the axial creep strain and axial steady creep rate of siltstone increase nonlinearly，while the instantaneous deformation modulus decreases logarithmically. The axial creep strain and axial steady creep rate increase significantly after the first wetting and drying cycle. The degree of deterioration of the instantaneous deformation modulus from 0 to 1 stage is the biggest which is 10.06%. The creep failure curve of siltstone under various wetting and drying cycles present similar regularities under the last level of stress. With the increasing of the number of wetting and drying cycles，the whole time for creep failure of siltstone decrease gradually under the certain failure stress，while the proportion of transient creep stage and accelerated creep stage in the whole time increase gradually. The long-term strength of siltstone decreases gradually with the increasing of the number of wetting and drying cycles. The largest reduction occurs after the first wetting and drying cycle. The creep failure characteristics of siltstone present a transformation from tension failure to shear failure.

A soft rock slope in the testing project of water diversion canal from Yangtze to Huai is reinforced with the reinforcement bars. The pullout experiment and stress relaxation test on glass fiber reinforced polymer(GFRP) bars and steel bars were carried out in the field in order to investigate the difference of anchoring performance between the GFRP bars and steel bars. The test results show that the ultimate bearing capacity of the GFRP bar is higher than that of the steel bar in soft rock slope. The GFRP bar has higher bond strength at interface than the steel bar. The GFRP bar deformed by breaking off above the grouted zone，whereas the steel bar was pulled out of the rock under the pulling force. The effective anchorage depth of the GFRP bar is shorter than that of the steel bar，and the axial force in GFRP bar degrades faster along the depth compared to that of steel bar. Compared to the steel bar，there is better deformation coordination between the GFRP bar and the grout，i.e.，the grout deformed together with the GFRP bar. The pre-stress attenuation rate of the GFRP bars is less than that of the steel bars. The pre-stress attenuation of the bars is due to the degradation of interface bond. The disturbance of the surrounding rock has also a direct effect on the pre-stress loss. The anchorage performance of the GFRP bar is better than that of steel bar，and its shear stress level is higher than that of steel bar when the interface bond degrades.

In order to investigate the initiation，propagation and coalescence of the natural stiff discontinuity，a series of uniaxial compression tests were carried out on two types of jointed marbles with different mineral contents and the evolution of rock deformation was captured using the digital image correlation(DIC) technique. Moreover，the scanning electron microscope(SEM) technique was used to study the characteristics of strength and deformation of jointed rock and failure mechanism as well as the structure-control effect. It was found that the whole mechanical properties of rock specimen were influenced by the relationship of the mineral contents between the discontinuity and host rock，that the strength of the rock specimen would decrease and the deformation was little when their mineral contents were different largely，and that the attitude of the discontinuities would take control of the rock fracture process when their mineral contents were similar. Based on the deformation field and strain field，it was better to describe the process of rock discontinuity from weak and non-continuous failure to strong and non-continuous failure. The existence of rock discontinuity did not make the rock specimens characterized with non-continuous properties during the initial loading stage. The rigid structure plane was less deformed before the destruction，and the damage occurred in a short time，resulting in the rapid release of energy. The results can help to explain the mechanical mechanism of rigid structure plane controlled rock burst.

Many disastrous events of impulse waves generated by landslides have occurred in the Three Gorges Reservoir since its impoundment in 2003. This paper describes systematically the purpose，content and object of risk assessment for landslide induced impulse wave in reservoir for the first time and gives the definitions to the relevant concepts and establishes the technical frame with five phases，including the scope definition，hazard analysis，vulnerability analysis，risk estimation and risk division. The risk assessment process of impulse wave in reservoir and the products in every phase are demonstrated through the potential rockfall at Banbiyan in Wu Gorge of the Three Gorges Reservoir. The main risk receptors of landslide generated impulse wave at Banbiyan are ships in the waterway，with the potential maximum direct economic loss of thirteen thousand Yuan to anchored boats and possible two sailing ships capsized. There is a high risk area about three kilometers long suffering from the landslide generated impulse wave at Banbiyan in the Yangtze River. A quantitative risk assessment system for landslide induced impulse wave is beneficial to delineating the risk point or region suffering from the impulse wave disaster，and ranking the risk order of many potential landslide-induced impulse waves.

It is not uncommon that a slope involves multiple possible failure modes. Monte Carlo simulation provides a way to estimate the failure probabilities of these multiple modes. However，it incurs frequent criticisms because of its low efficiency at small failure probability levels. To address this problem，a sample weighting method combined with the generalized Subset Simulation(GSS) is proposed in this paper to estimate efficiently the reliabilities of geotechnical structure system and the multiple failure modes involved in this system. The equations for calculating the failure probability at various failure threshold values of each mode are derived. The probabilistic fault tree model is employed to establish the limit state function of sophisticated system response. This limit state function of system is then incorporated into the driving variable of GSS to divide the whole random sample space into several mutually independent and collectively exhaustive sub-spaces. In the implementation of GSS，the probability weighting coefficients of different sub spaces are determined adaptively. With the probability weighting coefficients，the weighting coefficients of samples in each sub space are estimated properly，which can be further used to compute the failure probability of each failure mode in the system with different failure threshold values. A rock wedge slope is employed to demonstrate the performance of the proposed method. It was found that the proposed method improved significantly the computational efficiency in estimating the reliabilities of the multiple failure modes in the geotechnical structure system. The proposed method not only estimate the reliabilities of multiple failure modes through a single simulation and avoid the repeated simulation for different failure modes，but also enhance the efficiency of computing the failure probability of failure modes at low failure probability level. Moreover，it provides the failure probability values corresponding to various failure threshold values for all the modes concerned.

Conditional random field model can make best use of limited site investigation data to characterize the spatial variation of rock and soil properties more realistically. This paper aims to propose an analytical approach to simulate the 2D anisotropic conditional random field of rock and soil parameters. The procedure of implementation of the proposed approach is presented. A 2D conditional random field model based on the undrained shear strength is constructed and the slope reliability is updated based on the data of field vane shear tests from two boreholes. Then，an example of a clay slope under the undrained conditions is investigated to demonstrate the effectiveness of the proposed approach. The effects of the borehole location and layout scheme of boreholes on the slope reliability are also explored. The results indicate that the proposed approach can fully incorporate the limited site investigation data into the modelling of conditional random fields and realistic characterization of the spatial variation of rock and soil parameters. The obtained realizations of the 2D conditional random field by the proposed approach can reflect the inherent trends of increasing of means and standard deviations of rock and soil parameters with the depth，which make the results of slope reliability analysis more consistent with the engineering practice. The borehole locations and layout scheme of boreholes have the important influences on the slope reliability. The site specific test data acquired from the boreholes which are located in the vicinity of the slope toe can provide more value of information to the evaluation of slope reliability.

The characteristics of transient electromagnetic field in detecting shallow karst was studied focusing on the engineering and environmental problems caused by karst collapse. The shallow karst was generalized to be two types of geophysical models. The method of three dimensional finite difference in the time domain was used to simulate the transient electromagnetic responses. The resistivity，the karst size and the buried depth were selected as the comparison parameters. The numerically calculated differences of responses are bigger when the filled karst has the low resistivity and large size. The responses from the karst are mainly in the early stage. The transient electromagnetic field can identify nicely both the filled and half-filled shallow karsts. A field experiment was used to verify the numerical results in Guangxi. The transient electromagnetic profile revealed the known karst and found the unknown karst. The numerical and field experiments indicated that early observation and short time for turn off were better for small loop transient electromagnetic survey for shallow karst.

The whole process of strain energy conversion of shale in absorbing the axial strain energy ，storing and releasing the elastic strain energy ，dissipating the energy for plastic deformation and cracks propagation，expending strain energy for circumferential deformation was studied based on the energy theory and the shale tests under traixial cyclic loading. The variation of shale energy was revealed，and the criteria for strength failure of shale was established based on the energy catastrophe. The variation of behavior of shale specimen under the different confining pressures in the test of traixial cyclic loading was found to be similar and dominated by the energy accumulation before the peak stress，then the energy dissipation and releasing were predominant in the failure stage after the peak stress，the energy accumulation restarted after the shale specimen reached its residual strength，but its efficiency and capability was inferior to those before peak stress. In the failure stage，the elastic strain energy was released in large quantities along the main fracture，the dissipating energy  was consumed largely when the fractured rock mass frictionally slid along the main fracture，and the expending strain energy  grew substantially with the radial strain. Comparing with that before the peak stress，the magnitude of the elastic strain energy  and the dissipating energy in the stage of residual strength decreased substantially but have maintained stable while the expending strain energy increased a lot. The confining pressure did not affect much the energy ratio in the stage before the peak stress，but enhanced the efficiency and capbility of energy accumulation in the stage of residual strength. In the stage before the peak stress，the consumption ratio of elastic energy of shale and red sandstone decreased slowly with the axial strain，its changing rate went smoothly. In the failure stage，the inflection point of the elastic energy consumption ratio appears with a significant increasing in magnitude and growth rate.

As the large-scale water conservancy and hydropower projects was completed and put into operation，the long-term safety of rock mass engineering has become a hot issue for geotechnical researchers. In this study，systematic mechanical tests of marble were carried out，and a theoretical model for the time dependent strength was established. The mechanical properties，the failure mechanisms and the confining pressure effect of marble were studied through the uniaxial and conventional triaxial compression tests and the brittle-ductile conversion with the increasing confining pressure was concluded. The variations of mechanical parameters of marble under different plastic degrees were established through the cyclic loading and unloading tests. The variations of mechanical parameters with the time，the expressions of the aging plastic internal variable and the theoretical model of time-dependent strength of marble were established with the results of static fatigue tests. The mechanical parameters of marble degrade nonlinearly with time increasing and keep constant after two weeks.

The influence of complex geostress on the penetration depth of shaped charge into sandstone was analyzed and a formula for penetration depth under complex geostress was developed. The penetration depth of shaped charge into sandstone was simulated with the numerical method based on the constitutive model of sandstone and ALE algorithm. The influences of complex geostress on the shape of the hole and the energy of the sandstone during perforating were discussed. Comparisons of the results from the analytical analysis，numerical simulation and experiments were performed. The results show that the geostress has marked influence on the penetration depth. Compared to the geostress parallel to the perforating direction，the geostress perpendicular to the perforating direction has more pronounced effect on the penetration depth. Due to the greater geostress perpendicular to the perforating direction，the penetration depth becomes shallower，and the radius of the perforating aperture is larger. At the same time，the sandstone can absorb the elastic strain energy more. The proposed analytical equation and numerical method can simulate the penetration process of shaped charge into sandstone and predict the penetration depth respectively.

Due to the separate manufacturing of the upper and lower rock joints，the conventional molds have many defects，such as the large difference in performance between the upper and lower rock joints and the poor consistency in shear strengths. For the consistency of physical and mechanical properties between the upper and lower rock joints and the reliability of test result，a rapid and integrated manufacturing mold of rock joint has been developed by using the vertical surface plate for rock joint. The newly developed molds were mainly composed of the side plate，the bottom plate，the surface plate of rock joint，the screw rod，the nut and so on. It is not only simple in structure and convenient to be disassembled，but also low in cost and easy to be vibrated. The integrated and conventional molds were compared and analyzed regarding the smoothness of loading surface，surface porosity of rock joint，manufacturing period and result of direct shear test. The results show the integrated mold can realize the overall cast of upper and lower rock joints and ensure the consistency between the upper and lower rock joints. The rock joint panel placed vertically is found to beneficial to discharge the bubble and reduce the porosity by about 7%. The smoothness of the loading surface of sample is higer，which ensures the reliability and consistency of shear strengths of rock joint. Compared with the conventional mold，the integrated mold can shorten about 40% manufacturing period.

During the high temperature season of summer，frequent rainfall and evaporation result in that rock(rock mass) is under the alternate action of heating and wetting cycles. In this study，the variation of mechanical properties and the effect of heating and wetting cycles were investigated through the triaxial loading and unloading tests to intact sandstone samples under cyclic heating and wetting. The peak strength of triaxial loading and unloading of sandstone was found to decrease with the increasing of heating and wetting cycles and the degradation effect is more obvious in the early cycles. The failure mode of sandstone under triaxial compression after heating and wetting cycles is mainly the shear failures，which are the one with a single shear plane and the conjugated shear failure of “X”and“Y”type. The slipping phenomena appears in the failure surface and the damage occurs along the cone at the end of the sample. The triaxial unloading failures of sandstone under heating and wetting cycles are mainly the shear failure accompanied by the tensile splitting failure. Some specimens have the tensile and shear failures at the same time. The sandstone has more primary and secondary cracks，the modes of failure are more complex，and the extent of damage is more severe than the case of triaxial compression failure. The mechanical properties of sandstone decrease with the increase of heating and wetting cycles，and the trend of variation is consistent. The deterioration coefficient W due to heating and wetting cycles，that is，the absolute value of the coefficient of the term ln(n+1) in the normalized function，was defined to evaluate the deterioration degree of the mechanical parameters in the heating and wetting cycles.

The damage and fracturing of fractured rock mass under freezing-thawing and cyclic loading were studied. The quasi-sandstone specimens with a single joint of 0°，45° and 90° were prepared and tested under 0，10，20，30 cycles of freezing-thawing. The damage characteristics and fracturing features of quasi-sandstones with a single fracture under the combined effects of freezing-thawing and cyclic loading were discussed. The damage characteristics of the fractured rocks are related to the fracture morphology，the number of freezing-thawing cycles and the cyclic loading mode. There exist the typical coupling effects between the number of freeze-thaw cycles and the cyclic loading processes. The failure strength is directly proportional to the crack angle after the cyclic freezing-thawing，which is much different from the cyclic loading test without the effect of freezing-thawing. With the increase of cyclic loading level，the hysteresis ring tends to be full，and the migration pattern is presented due to the differences of the crack angles. In addition，the degree of fullness of the hysteresis loops located in the center are less than the ones located in the boundaries. The expression of defect area can reflect accurately the localized damage at fracture tips under the combined effects of freezing-thawing and cyclic loading.

In order to identify the spatial location of the critical blocks in rock slopes，a theory which describes the interaction among the rock blocks by cross-impact analysis was put forward. The method of predicting the uncoordinated deformation regions，distinguishing the critical blocks，evaluating the reinforcement effects was introduced as an example in the feedback analysis of Dagangshan slope. Compared with the traditional time series analysis，the cross-impact analysis requires less incremental displacement information and achieves the spatial distribution of critical block efficiently.

Multi-failure modes inherently exist in geotechnical engineering practices，which are typically considered as series system problems in literature. However，the existing system reliability methods can hardly achieve a good balance between the computational cost and accuracy. Given this limitation，a novel method integrates a highly efficient second order reliability method(SORM) and a practical system reliability approach was proposed in this paper. Specifically，the quasi-Newton approximation-based SORM was used to approximate the second order reliability index for each limit state function(LSF)，providing a basis for the further linearization transformation，so as to ultimately implement the improved linearization approach to obtain the system reliability results. In addition，two examples of common geotechnical problems featuring series system reliability analyses-a semi-gravity retaining wall and a soil slope with multiple layers were reviewed for illustration. The computed results with the proposed method show good computational efficiency and accuracy.

In order to research the mechanism of and influencing factors in progressive failure of contact surfaces of soil-structure，a new stress-displacement sensor was developed and large direct shear tests on the contact surface between red clay and structure were performed. The stress and deformation of the contact surface between red clay and structure under shear were analyzed and the progressive failure mechanism of the contact surface was investigated. The test results indicate that the peak shear stress and displacement of the contact surface occur successively along the shear direction and that the contact surface fails progressively. It was also found that the normal stress on the contact surface and the compaction degree of the soil influence significantly the progressive failure. The time difference to reach the peak shear stress at measuring points along the shear direction increases with the rising of the normal stress on the contact surface，but decreases sharply with the ascending of the compaction degree of the soil. The contact surface presents more remarkable progressive failure behavior with a lower compaction degree.

In order to obtain the p-y curves of laterally loaded piles in sand，a series of model tests including four battered piles and one plumbed pile embedded in the medium-dense dry sand were conducted and the relationship between the soil resistance p，and the lateral displacement y，of pile shaft was obtained by fitting the model test results. In addition，the stress-strain ( - ) curves for the sand used in the model tests were obtained based on the tri-axial compression test. A new p-y curve for laterally loaded batter piles was proposed according to the relationship between the dimensionless p-y expression and the dimensionless - curves. The methods to determine the parameters in the p-y curve were also given. The comparisons between the calculated results based on the p-y curve proposed，the model test results and the centrifuge model tests from references demonstrated that the p-y curve proposed for the laterally loaded batter piles was reasonable and can be used to describe the complex compression and shear behavior between the inclined piles and the surrounding soils. Finally，The p-y curves were used to analyze the behaviors of the inclined piles under different conditions and it was found that the lateral displacements and the maximum bending moments induced in the batter piles with the head fixed are less than that of batter piles with the head free. The existence of the vertical load on the pile head can reduce the lateral displacement and the bending moment in the negative batter piles but increase that in the positive batter piles. The increment of the stiffness of inclined piles can effectively reduce the lateral displacements and the maximum bending moment of the piles.

Large-scale direct shear tests were conducted to study the effects of roughness on the mechanical behaviors of concrete-sand interface. The distribution frequency of the bulge size of concrete surface was obtained using the method of statistical analysis based on the curves of the diameter of holes versus depth of bored piles. The concrete slabs with the smooth surface and regular grooves were manufactured to simulate the surface roughness of concrete structures in engineering practice. A new method was proposed to calculate the surface roughness(R) of concrete considering the groove geometry，the disturbed soil volume and the efficient width of groove. The shear band thickness was found to be about 5 times of the average diameter(D50) for the coarse sand and fine gravel with a D50 value greater than 0.7 mm. The peak stress ratio increased approximately linearly with R in a semi-logarithmic scale for concrete-sand interfaces with regular grooves，and the peak and residual stress ratio decreased with the increasing of normal stress. The interface dilation angle increased with the increasing of R but decreased with the increasing of normal stress，implying that the high normal stress restrained the interface dilation behavior and reduced the effects of R on interface dilation. The normalized interface friction coefficient (Ep) increased linearly with R in a semi-logarithmic scale and became greater than 1.0 when R was greater than 0.70 mm. It is thus concluded that the shear strength of sand may not be the up limit of shear strength of concrete-sand interfaces with regular grooves because of“passive resistance”.

Soil-rock mixture has the characteristics of distinct heterogeneity，obvious structural and size effects，and thus has the complex mechanical properties. In this research，the deformation properties and the influencing factors of shear band of soil-rock mixture during the shearing process were investigated with the servo motor controlled system of geotechnical experiment developed in-house(RSM-1000). The shear band deformation tests on soil-rock mixture were conducted considering the effects of different rock contents(0，30%，50%，70%)，normal pressures(50，200，300，400 kPa) and rock sizes(L1，L2，L3) respectively. The deformation characteristics of shear band were monitored by putting the aluminum wires and dry ash into the hole inside the samples. The results show that when the rock content is less than 30%，rocks have little effect on the deformation of samples，and that the mechanical strengths of samples mainly depend on the sand. When the rock content reaches 50%，samples are transformed into a skeleton structure，rocks have obvious effects on deformations and the mechanical strengths of samples are affected by rocks and sand simultaneously. When the rock content reaches 70%，samples are transformed into the rock structure with empty space. Under the condition of high rock content and rock particles of large diameter，the rocks through the shear surface tend to extrude and roll during the shear process. The rocks around the shear surface are mainly affected by dilation，and present extrusion，particle breakage and redistribution. The shearing deformations of the samples are comprised of three distinct stages and can be depicted as the failure of thrust landslide with the deformation from back to front or compound landslide with the deformation from two slides to the middle. At the first stage，the cracks were generated on the top of the backward slope under the effect of active soil pressure，which leads to the sink，compaction and instability of the top of backward slope. Then，the front edge of the slope begins to deform and move forward. Finally，the shearing dislocation of the soil-rock mass and the progressive expansion failure of the sliding face result in the cut-through of shearing plane and the whole destruction of the slope.