Brazilian splitting tests were conducted on standard granite discs treated under 25 ℃，200 ℃，400 ℃，600 ℃，and 800 ℃，respectively，to investigate the macroscopic physical and mechanical properties，including tensile strength，volume expansion ratio，P-wave velocity. In addition，temperature effect on microstructure and acoustic emission(AE) characteristics of granite was studied. Results show that：(1) Scanning electron microscope (SEM) inspections reveal that there exist temperature-induced microcracks within the granite discs，including intragranular crack，intergranular crack and transgranular crack. With the increase of temperature，the number，extension length，opening width，and extended range of microcracks increase monotonically. The temperature sensitivity of different mineral compositions are different；(2) After high-temperature treatment，the tensile strength decreases，the volume of granite disc expands，and the P-wave velocity reduces；(3) The P-wave velocity drops sharply and the crack density of granite sections increased sharply in the range of 400 ℃–600 ℃，indicating a thermal damage threshold within this temperature range；(4) Results of AE events show different characteristics of AE temporal sequences of discs treated by different high temperature，and the number of AE events during the loading process of the discs treated by the higher temperature(600 ℃ and 800 ℃) is obviously less than that of those treated by lower temperature(≤400 ℃)，moreover，the increasing range of AE events decreased significantly before the splitting of the discs，and the correlation between the AE locating results and the macroscopic splitting cracks is weak.

A numerical model was presented in this study to analyze the load-transfer mechanism of fully grouted rockbolts，which was based on the bi-exponential shear-slip model of the anchorage interface and the linear enhanced elasto-plastic constitutive model of the rockbolt. It was validated by pull-out tests. The load-transfer characteristics with different anchorage lengths were studied in detail. The distribution of axial stress and shear stress along the rockbolt with anchorage length of 1.5 m was examined. The numerical results showed that it could not only describe the failure modes of interface slippage and tensile failure of rockbolts，but also determine whether the rockbolt yields during the full-range process of pullout. The reliability and accuracy of the proposed analytical model were verified by experimental pullout tests.

Deep rock engineering is in a high stress disturbance environment，and high temperature must be taken into consideration，dynamic compression characteristics are important for evaluating the stability of surrounding rock，which is different from the shallow. In order to get the dynamic mechanical properties of rock suffered both temperature and water. By using the system of Hopkinson pressure bar，dynamic uniaxial compression tests of Fangshan marble in dry and saturated conditions are carried out in four temperature gradients(25 ℃，105 ℃，450 ℃，700 ℃). The dynamic compression characteristics of small porosity rock under the action of temperature and water are studied. The results show that the longitudinal wave velocity increases at first and then decreases，and starts decline sharply after 450 ℃. The dynamic uniaxial compression strength of dry and saturated marble gradually increases linearly with the increases of loading rate in every temperature，and rock after temperature damage is more obvious than room temperature. Compression strength of thermal damaged rock assumes a downward trend as the temperature increases. The compression strength of saturated specimens is almost same as dry specimens in 105 ℃，and the dynamic compressive strength of saturated rock is higher than that of dry rock at 450 ℃，while the strength of saturated specimens can be higher than dry ones when loading rate(after 1 500 GPa/s) is high enough in 700 ℃.

Former studies of hydraulic fracturing experiment are usually restricted to the description of fracture geometry and lack the analysis of pump pressure data. To solve the mentioned problems，triaxial hydraulic fracturing experiment is carried out. Combining acoustic emission data with the fracture geometry after experiment，the influences of vertical stress difference coefficient，fracturing fluid viscosity and displacement on hydraulic fracture propagation behavior are studied. The pump pressure signal is wavelet-decomposed to study the relationship between pressure characteristics and fracture propagation behavior. The results show that，vertical stress difference coefficient，fracturing fluid viscosity and displacement have large influences on fracture interaction behavior and fracture propagation velocity，thus affecting the ultimate fracture geometry. Moreover，the detailed information of pump pressure is consistent with the acoustic emission energy curve and fracture geometry. Therefore，it can be used to identify the fracture initiation and interaction behavior. This study provides some guidance for the hydraulic fracturing operation in field.

Retrogressive slide of natural slopes is often caused by the down-cutting of valley and excavation in the toe of slope and further forms multi-stage trailing edge tension crack surfaces in the rear of slope body. And the formation mechanism of the trailing edge failure surfaces plays a pivotal role in the stability analysis of the retrogressive landslide. So，model tests and theoretical analysis are carried out to research on the formation mechanism in this paper. A test device is developed to simulate both the softening effect of the groundwater on the sliding zone and progressive failure characteristics of the landslide. The sectional sliding surface，which is a part of this device and composed of several permeable boxes，can simulate sliding surfaces with different geometric shapes. The sliding zone can be simulated to be saturated and softened in stages by injecting water into different permeable boxes，so that the various failure modes can be simulated. Four kinds of test schemes are designed to simulate the circular，fold line and linear sliding surfaces. Meanwhile，three steps and two steps of slope surfaces are also simulated. Considering three stages of the landslide condition，every fracture angle of the trailing edge of the slip body is measured. The model test results indicate that the experimental value of the inclination of the trailing edge is obviously affected by the thickness of the sliding body and the location of the unstable slip section. It is assumed that the possible formation mechanism of the trailing edge of retrogressive landslide may be the overall sliding，the sliding tension crack and sliding shear failure，and the inclinations of the trailing edge are calculated. The results show that the calculated values of the sliding tension crack mechanism are the closest to the experimental ones，and the relative error is less 10% than the experimental value. It is considered according to the results that the formation mechanism of the trailing edge of the retrogressive landslide is：the bottom of the slip surface loses its stability and slides down，and tensile failure zone appears at the location of sliding body corresponding to the end of the unstable slide surface. The tensile stress is controlled by the minimum principal stress，and the direction of the tensile failure surface is basically in agreement with the maximum principal stress.

In order to describe the effective stress characteristics of rough rock fractures，an effective stress coefficientis introduced through the stress balance analysis on the basis of the established asperities-voids-water pressure conceptual model of the rough fracture. Then，the quantitative relationship between the coefficientand the confining stress and water pressure is investigated using the hydraulic test results of two single fractured sandstones. On this basis，a new effective stress model regarding the rough fracture is built，and meanwhile，the applicability of the traditional model is discussed. The results show that the ratio of interconnected voids in the fracture，been assumed as the effective stress coefficient，is capable of describing the variation of hydro-mechanical coupling behaviors of rough fractures well. The empirical model shows a good representation of the changes of the coefficient with the confining stress and the water pressure. Besides，the effective stress values calculated by the new and traditional models，respectively，show a significant difference at high confining stresses and high water pressures. Furthermore，the critical confining stress and water pressure can be used to estimate the applicability of the traditional model. The former is related to the sensitivity of the effective stress coefficient to the confining stress，and the latter linearly increases with confining pressure.

The cracks，existing inside the engineering rock mass，are easily to propagate and coalesce under the disturbance of construction，which will threaten the safety of construction. Firstly，a statistical damage constitutive model was proposed to describe the influence of microcosmic cracks on the stress state of rock mass. Then，a modified NMM was proposed to consider the influence of rock damage. The calculation format of the modified NMM stiffness matrix and load matrix for damage constitutive equation under the plane condition and equations of stiffness matrix and incremental iterative were also established. Besides，the modified Newton-Raphson method was used to solve the nonlinear equations of the modified NMM and corresponding algorithm was also introduced. Finally，the effectiveness is verified by a typical example and the calculation differences of the present and modified NMM are discussed. Furthermore，fracture propagation and failure process of a roadway in the Yi coal mine of Pingdingshan was simulated to validate the effectiveness of the proposed method. Because the modified NMM considered the influence of microcosmic cracks on specimen damaging and strength declining，which decrease the initiation and failure strength，as a result，the proposed method can describe the mechanics behavior during loading more reasonable. The research in here is important for scientific designing and safe construction in fractured rock mass.

In order to study the mechanism of multiple-fracture unevenly growth in multi-cluster fracturing，we simultaneously consider the stress interference among fractures and dynamic flow distribution among clusters to establish a set of control equations for multiple-fracture propagation within a stage，and the equations are solved by Picard iteration method. In the model the multiple-fracture propagation velocity is determined by the energy release rate. The stress interference and fracture width are calculated by displacement discontinuity method，and dynamic flow distribution among clusters are calculated according to Kirchhoff¢s second law. Based on the established model，an example of X201 well in Xinjiang is analyzed. The results show that when the cluster spacing is 20 m，interior clusters are severely restricted. Under the condition of four clusters fracturing，only increasing the internal clusters spacing has little influence on promoting multiple-fracture even propagation. Adjusting perforation friction can promote internal two clusters effective extension. Simultaneously adjusting the clusters spacing and perforation friction is more likely than only adjusting one to promote multiple-fracture uniform propagation.

Dynamic mechanics and damage characteristics of deep sandstone after different temperature treatments in impact failure process were studied using split Hopkinson pressure bar(SHPB) system. The variations of dynamic mechanical parameters(such as dynamic stress，strain，strain rate，fractal dimension，failure mode and damage degree) of deep rock with temperature were analyzed. Test results show that 20 ℃ is the turning point of dynamic mechanical parameters with the temperature range from －15 ℃ to 800 ℃. The dynamic peak stress of sandstone increases with the increase of temperature from －15 ℃ to 20 ℃， and the corresponding inflection point appears at 0 ℃. Meanwhile，the dynamic peak stress decreases with the increase of treatment temperature from 200 ℃ to 800 ℃，furthermore，it decreases sharply when the temperature over 600 ℃. The experimental data shows that there is an obviously strain rate effect for test sandstone after different temperature treatments，and the failure modes of samples are two typical kinds：splitting failure and crushing failure. Additionally，the temperature has significant effect on the damage evolution process of sandstone.

In order to study the size effect of rock mechanics under high strain rate，f50 mm split Hopkinson pressure bars(SHPB) was used to carry out impact loading test for 12 types of limestone specimens with diameter of 50 mm and length of 15 mm to 100 mm. The results show that the single axis dynamic compressive strength of limestone specimens has obvious size effect，and the dynamic compressive strength increases first and then decreases with the change of the length of the specimen. The strength of the specimen is the maximum at the length of 60 mm，and the stress strain curve of the specimen with a length of 15 mm to 35 mm is larger and the length of the specimen is more than 35 mm. With the increase of the length of the specimen，the stress strain curve generally has little change. With the increase of the length of the specimen，the peak strain of the specimen decreases，and the dynamic elastic modulus of the specimen increases first and then decreases when the length of the specimen is 60 mm，and the fracture degree is first with the increase of the length of the specimen. There is a correlation between the decreasing trend and the increase trend. The greater the strength is，the weaker the failure is.

Coal permeability is the key factor determining the effectiveness of coal-bed methane(CBM) exploitation. In the CBM production cycle，the long-term high temperature and stress make the seepage paths in coal evolve with time. In this paper，the seepage evolution in coal creep under different temperatures and different stresses were studied，and the results shown that the creep of coal undergoes three phases：the hardening phase before the creep start stress threshold，the creep phase with compressive volume deformation and the creep phase with expanding volume deformation. In the whole process，the permeability of coal gradually decreases and then increases with the creep strains and there is a good consistency between the permeability evolution and time-dependent volumetric strain. The increasing temperature is helpful for the occurrence of coal creep strain，resulting in the decrease of the creep start stress threshold and the ultimate failure strength. At high temperature，the creep of coal shows a greater influence on the decrease of permeability，and the maximum loss of coal permeability can reach 40.35%. The results can provide theoretical support for the effective exploitation of CBM.

The mechanical and acoustic characteristics of yellow sandstone under small-size effect were studied. The rock strength，deformation，elastic constants(elastic modulus，Poisson's ratio)，failure morphology and energy conversion law under small-size effect were discussed. The relationships between the acoustic emission energy，the count，the peak frequency and the size were analyzed. As the size increases，the strength decreases linearly，and the radial strain extends from the oblique to the horizontal direction and exhibits a tendency to decrease first and then to stabilize，and the axial strain gradually reduces. Body strain increases first，then stabilizing and then decreasing. The rupture range decreases gradually. The shear angle decreases first and then increases. The elastic modulus and Poisson's ratio show an increasing trend. The energy after the peak shows a release law of accelerating first，then stabilizing and then decreasing. With the decrease of size，the dissipated energy and the total energy accumulated before the peak show an increasing trend，the dissipative energy acceleration phase and the deceleration phase are gradually decreasing，and the stabilization phase is gradually extended. There is a tendency of “closed-cup” between energy，elastic energy，release energy and surplus energy all show a decreasing trend，acoustic emission energy and time show a“double peak”image. The emission count and energy show“horn” expansion，while high energy，high meter，high peak(three high) can predict the impending destruction of the rock；as the size decreases，the total energy of the acoustic emission appears after the peak interval is counted. The total energy of the acoustic emission is proportional to the size. The characteristics of acoustic emission peak frequency is obvious partitioning.

Debris-flow impact force exhibits strong randomness due to irregular shape and motion of coarse particles in the flow. In order to examine the influence of grain size on the impact force and its characteristics of random distribution，seven groups tests of debris-flow impact forces were carried out by large-scale flume in the Dongchuan station，Chinese Academy of Sciences. The material used in the tests originates from Jiangjia Ravine′s debris-flow deposition and the grain size is up to 8 cm. The experimental results indicate：the dimensionless impact force of debris-flow increases with the dimensionless maximum size of coarse particles，and there is a good exponential empirical relationship between them. The Log-Logistic probability density function is the best one to describe the distribution of the impact force among six probability density functions. The values of the Log-Logistic function′s scale and shape parameters increase with the dimensionless maximum size of coarse particles，showing the logarithmic empirical relationships between the parameters and size.

The constant resistance and large deformation bolt(CRLD bolt) which working resistance is 130 kN and has widely been used as rock support in longwall mining based on gob-side entry retaining without coal pillar(110 mining method) was selected as the sample. In order to investigate it′s dynamic response characteristics，the SHTB tests were carried out on the modified SHTB system which modified by HE Manchao. In the test，quartz piezoelectric force sensor and laser displacement sensor were used to monitor the impact force and impact displacement response of the CRLD bolt at different impact speeds. The test results show that，under the impact load，the impact force and the elongation speed of the bolt both reach the peaks within 0.5 ms，and the CRLD bolt can respond rapidly to the impact. Under different impact velocities，the impact force and deformation velocity of CRLD bolt are both a fluctuation which going through a time developing process. The deformation of large deformation bolt with constant resistance is a process of elastic-slip-elastic recovery.

In order to study the damage and permeability enhancement of coal rock due to cold shock，NMR (nuclear magnetic resonance) and permeability test were conducted firstly before and after liquid nitrogen soaking，by analyzing the changes of T₂ distribution，T₂ spectral area and permeability，pore damage and permeability evolution properties were studied. Then，the relationship between temperature drop and the evolution of pore damage and permeability were discussed. The results showed that the number of pores，the porosity and the permeability of coal rock are increased after liquid nitrogen soaking. Coal rock permeability is improved after first cold soaking circle，but almost has no change in next few circles. The permeability of coal rock increases at first and then tends to be stable with the increase of freezing time. The evolution of coal rock damage and permeability are dominated by temperature drop，the bigger the temperature drop，the more severe the damage and lager permeability increment to coal rock. Coal rock permeability change caused by cold shock is almost linear to temperature drop，when the temperature drop of coal rock reaches the maximum，the damage is terminated and the permeability cannot be increased even though the freezing time is increased. By freezing coal rock at room temperature with liquid nitrogen，the permeability increment of coal rock is between 50%–150%.

Mechanical interaction between a hydraulic fracture and a natural fracture is a crucial issue for analyzing hydraulic fracture growth. The complementary constraints of natural fractures were derived from the deformation and stress state of natural fractures，then the mechanical model for solving interaction between a hydraulic fracture and a natural fracture was established based on boundary element method. The model was validated by the analytical solution of frictional cracks and the trial method for solving mechanical response of natural fractures. A case study was conducted based on a multi-staged fractured horizontal well of shale gas，and mechanical response characteristics were investigated by the new model. Results show that results calculated by the model are consistent with the microseismic measurement result. When a hydraulic fracture contacts with a natural fracture，the hydraulic fracture tip can be blunted. The natural fracture can be opened and slipped near the contact location，and slipping zone is larger than opening zone. When the approaching angle is larger than 60°，opening of the natural fracture is difficult to occur. The initiation location of a natural fracture is not coinciding with the contact location. The hydraulic fracture has more chances to penetrate the natural fracture under the condition of large approaching angle，net pressure and friction coefficient.

Under the cyclical elevation of reservoir water level，the rock mass in the sinking zone of bank slope is in a wet-dry cycle. The joint zone and full-fledged development of the fluctuating zone directly affect the deformation and stability of the reservoir bank slope. The dry-wet cycle test of rock mass joint surface was designed，and a multi-access repeated shear test method and data correction method for jointed surface was proposed. The test results show that：(1) Under the action of dry-wet cycle，the shearing mechanical properties of jointed surface have obvious deteriorating effects. With the increase of dry-wet cycle，the shear stress-shear deformation curve gradually moves downwards. The slope of the plastic hardening stage gradually decreases，and the tangential displacement at the shear yield point gradually increases. (2) The shear strength of the modified front and rear jointed surface is steeper as the cycle of wet and dry cycles increases. The deterioration trend is slow，and the shear strength degradation caused by the first eight dry-wet cycles action is large. (3) The law of deterioration of shear strength of jointed surface is closely related to the process of dry-wet cycle，and the lubrication，softening，the dissolution，erosion of the cement，and the water-rock geophysicist effects of various feldspar minerals have resulted in deterioration of the mechanical properties of the jointed surfaces. The related research results can provide a good basis for long-term deformation and stability analysis of bank slopes.

True-triaxial unloading rock burst experiments on granite samples were conducted with the acoustic emission(AE) transducers being placed directly on the rock sample and on the rock-sample holding plate respectively，in order to obtain the precise information for rock burst tests based on AE signal analysis. Six key waveforms of the AE data selected according to the three typical rock burst failure stage were selected from the AE data in each of the rock burst experiments for the comparative analyses. The results illustrate the fact that the holding plate is equivalent to a low-pass filter filtrate the low-band information of the AE signal which is the important information about the rock macroscopic failure；AE acquired in the transducer directly mounted on the rock sample have the whole band information indicating the microscopic fracturing till eventual macroscopic failure. Besides，the holding plate damps the magnitude of the AE signal，that is，the signal-to-noise ratio is reduced，which may make it difficult to identify some main amplitude information.

Here the dynamic method of caustics was used to study the stress dynamic fracture behavior of anisotropic brittle materials by considering anisotropic stress distribution near the crack tip. The stress intensity factor and crack length versus time，and the fracture toughness were obtained. Results show that the fracture toughness of the specimens after plastic compression are different from that uncompressed specimens. And the fracture toughness of specimens transversely cut and axial crack propagation(TA) were larger than that transversely cut and transversely crack propagation(TT). The fracture toughness increases with compressive strain increases. The reflective method of caustics can be applied to non-transparent materials，which could be extended to the dynamic fracture analysis of anisotropic brittle materials such as rocks.

Study on the mechanical characteristics of stick-slip and the observation of rupture propagation on faults are in favour of getting insight into the earthquake source process. To mimic natural earthquakes，in this paper，the scheme of laboratory earthquake was performed where the gabbro sample of straight fault was loaded bi-axially. The effect of loading rate in the range of 0.05–0.5 μm/s on the stress strop and recurrence interval of stick-slips was investigated. Based on the ultrahigh speed diagnostic system with digital speckle，the dynamic rupture propagation of the fault was captured. With the digital image correlation(DIC) method，the evolution of the displacement field and the shear stress field was resolved. It is revealed that：(1) the recurrence interval，average stress drop and the dislocation of ruptures increase while the loading rate decreases. (2) There can be more than one nucleation region on the earthquake fault and the observed rupture process consists of the nucleation stage，the slow coalescence stage and the rapid propagation stage where the rupture speed can approach or even exceed the shear wave velocity. (3) The asperities and weak segments on the fault are responsible for the complex of the dynamic rupture propagation process and the heterogeneity of dislocation along the fault trace.

In order to realize the simulation of dynamic process of debris flow，the dynamic process of Val Pola debris flow in Italy was simulated using continuous theory method and discrete theory method. In the continuous theory method，the HLLC approximate Riemann solver has been used to calculate the interface flux of the control unit of the finite volume numerical discrete. Then，the results of two kinds of simulation methods were compared and analyzed. The simulation results show that the calculation results of the two kinds of simulation methods，such as disaster scope and motion time，are in good agreement with the actual disaster situation，and it is a good representation of the dynamic process of disaster，which verify the effectiveness of two kinds of simulation methods. The results of velocity of the two simulation methods are relatively close to each other，which can provide an effective reference for the research of the velocity of Val Pola debris flow. The computational efficiency of the continuous theory method is better than that of the discrete theory method，while the influence of local topography on debris flow can be observed using the discrete theory method.

In order to study the change of shear mechanical properties of different natural rock materials before and after anchoring，three representative rocks of white sandstone，marble and granite were selected，and the direct shear test was carried out after the rocks were drilled，anchored and cured. Each rock material is divided into two kinds of conditions，anchorage and without anchorage，three normal stress levels are adopted in the test. The stress and deformation characteristics of different natural rock materials under different normal forces and shear forces are explored，and the influence of the normal stresses and rock properties on the shear mechanical properties of anchoring jointed rock mass is compared and analyzed. The experimental results show that there are some differences in the anchoring mechanical properties between natural rock and the rock-like material such as cement mortar，the equivalent cohesion and internal friction angle of rock joint surface can be increased by bolt anchorage. The compressive strength of the rock material has a significant effect on the mechanical properties of the bolted joints，the weaker the rock is，the more similar in the anchoring mechanical properties of the rock and the rock-like material are; the harder the rock is，the greater the increase in the shear strength of the anchoring joints，the more significant in the reinforcement effect.

Based on the shaking table model test，the characteristics of deformation and failure of the slope under different ground motion intensity are studied in the loess-weathered rock contact surface slopes in Haitou Village，Tianshui，Gansu Province. Furthermore，the development of vertical cracks during the period of crack generation，surface peeling and slop slide were analyzed. Combined with the results of soil strain test，the mechanism of the slope instability and the derivation of the slip surface are revealed. The results show that the influence of vertical loading on the model is less than that of horizontal under the same seismic intensity. The vertical direction of soil is easily to induce vertical crack while the horizontal is more intend to induce transverse crack. Moreover，vertical crack is the main cause of surface friability，but transverse crack is the main driving force of slope instability. At the top of the slope，the composite failure of tension and shear occurs under the action of seismic load，which leads to the downward transition of the transverse surface of the slope to the contact surface of the loess-weathered rock，forming the slip surface of the slope failure.

The cause of rockbursts is associated with the variation of the abutment pressure in surrounding rocks. Based on the case of the LW1301 in Yuncheng Coal Mine，this paper aims to explore the mechanism of the rockburst occurrence under a specific condition of little mining influence. Theoretical analysis，field monitoring，and an engineering test were used to investigate the stress distribution characteristics in the surrounding rocks of a water sump，and their property change. The research work involves：(1) a new rockburst type of static-stress rockburst and its occurrence mechanism. (2) Stress distribution characteristics in the surrounding rocks of the water sump，and (3) the change of the rock and coal property around the water sump through a water immersion test for a month. The study reveals that the rockburst event occurred in the LW1301 in Yuncheng Coal Mine on January 8 is induced by the failure of the weakened coal pillar in the water sump，leading to the transformation of the roof structure and the stress redistribution in the surrounding rocks. The results of this work can provide a reference for rockburst preventions of other longwall panels with similar conditions.

The influence of uniaxial static load and cyclic impulse on the damage of coal rock is studied by using the restraint pendulum impact dynamic loading test device and the ultrasonic testing device. A damage model of coal rock microfracture is established，and the criterion of coal and rock damage is given. The damage amount of coal rock increases with the increase of impact load and decreases with the increase of static load. Experimental results show that the coal rock damage amount is a cumulative effect，the damage increases with the increase of impact times；the same total impulse effect on coal rock，cumulative damage cumulative amount of damage formation was significantly greater than the increase of constant impulse；incremental impact，coal rock cracks accelerated expansion，coal has accelerated destroy the trend of constant impulse impact，coal rock cracks of coal rock have to slow down the expansion，the trend with the increase of damage reduction；static axial pressure，the change of coal rock damage amount is easing，cumulative damage reduction，increase the anti shock capability of coal rock destroyed the need to impose impact times increased.

The failure of open-pit mine jointed rock slope generally includes translational and rotational mechanical effects. The stability of jointed rock slope with sliding and toppling failure is studied，by combining plastic limit analysis theory，discrete technique of rigid block element with multiple degrees of freedom，the principle of pseudo-static method and mathematical programming method. The seismic inertia forces of elements are calculated according to the pseudo-static method. After that，taking internal force vector(normal force，shear force and bending moment) of interfaces as decision variables，the static admissible stress fields of jointed rock slope are constructed，and the mathematical programming model of lower bound method for jointed rock slope stability analysis is established. At the same time，taking the translational velocity and rotational velocity of element centroid as decision variables，the kinematically admissible velocity fields of jointed rock slope are constructed，and the mathematical programming model of upper bound method for jointed rock slope stability analysis is established. Lastly，the optimization algorithm are employed to solve these two models，and the upper and lower bound solution of the safety factor and corresponding failure mechanisms of jointed rock slopes can be obtained.

To investigate the combined effects of water saturation and loading rate on rock mechanics，a series of dynamic compression，tension and fracture tests are conducted on both dry and saturated sandstone specimens using the split Hopkinson pressure bar(SHPB) system. Test results show that，under static loads，both strength and fracture toughness have different degrees of reduction after the specimen was saturated. Under dynamic loads，the strength and fracture toughness increase with the increase of loading rate，and the saturated specimen has higher rate dependences for each mechanical property compared with that of dry ones. Under high loading rates，free water inside the rock specimen can induce inertial effect，meniscus effect and viscosity effect，which prevent the initiation and propagation of cracks. Particularly，when the loading rate exceeds 1 290 GPa/s，the compressive strength of saturated specimen can even be greater than that of dry specimen.

It is a significant task for rock mass stability monitoring to study coupling properties of stress and acoustic emission(AE) of coal and rock fracture under multilevel dynamic loadings. This paper is aiming at revealing relations of stress and AE of coal and rock samples under multilevel dynamic loadings. Stress and AE synchronous data has been obtained from mechanic properties testing system of coal and rock samples under multilevel dynamic loadings. The results show that the accumulation stress of coal and rock under multilevel dynamic loadings is obviously less than the maximal compression stress. Then，multilevel dynamic loadings could induce cracks extension according to the felicity effect of coal and rock. Memory characteristic of rock stress shows obvious felicity effect and the felicity ratio presents a decline trending with the larger level dynamic loadings. Also，fractal dimension between stress and AE has been calculated by using of GP algorithm，which could explain the perform of felicity effect reasonably. Coulping properties of stress and AE show more obvious on fractal structure characteristics. The fractal dimension is relatively larger. The felicity effect is not obvious and the fatigue damage and structure defect degree is lower，which show the negative correlation.

It is important to understand the stage division and its AE characteristics during rock deformation process. This helps when making prediction about the rock¢s stress state. With an example of siltstone，the AE characteristics for each of seven stages of the whole stress-strain curve were given in this paper. AE characteristics applied for this purpose were combined by three aspects. They are curves of AE events accumulation vs. time，AE frequency distribution scattering vs. time and AE events locations in rock space by stages. For convenience to making more accurate descriptions of AE temporal-spatial evolution，some definitions of typical characteristics for the above three AE aspects were given firstly. According to their geometric form, the AE characteristics were described as AE platform，AE multistep upward，band of major frequency，cutting frequency，intensive gathering，etc.. Secondly, experiments of monitoring and 3D location of acoustic emission(AE) were carried out on siltstone during its deformation under uniaxial compression. It is investigated temporal-spatial evolution characteristics of AE in each stage of the process. It was found to be identifiable for each of the seven stages by application of the three combining AE properties. Upon meso-mechanical analysis，the comprehensive evolution state of AE may be greatly influenced by fracturing mechanism. This mechanism is determined by local stress state in rock and sizes and azimuth of the original fissures therein. Similar to process of elastic rebound in earthquake，the process of shear localization in rock was formed by AE events gathering around micro structure therein during the softening stage(the 4th stage). This leads to stress drop with major fracturing in rock. Then more AEs were triggered by meso-fracturing process with release of strain energy during elastic rebound. Thus the combining three AE properties in the 4th stage，i.e. AE platform，AE multistep upward，band of major frequency in a line shape with cutting frequencies，AE intensive gathering in several zones of rock space，would be taken as precursors prior to rock failure. Finally，the three combining AE properties were compared on other three different kinds of rocks. It was concluded that AE properties were controlled by triggering process of ultrasonic with meso-fracturing. The harder and bigger the mineral particles，stronger cementation between them，and more micro structures distributed in rock homogeneously，the more AE events，more frequency bands and cutting frequencies produce. Therefore，it is necessary to investigate systematically influences of meso-fracturing by rock¢s micro structure when applying AE properties to monitoring and indentifying stress state of rock during its loading process.

Abnormal deformation of valley in the initial impoundment period is a new problem of super high arch dam in China. It is urgent to study the deformation mechanism of rock mass from unsaturated seepage to saturated seepage. Based on the transition process of rock mass from unsaturated seepage to saturated seepage，the governing equations of rock mass under the interaction of unsaturated seepage and stress are derived. The hydraulic coupling model of unsaturated rock mass is established，and it is applied to the deformation analysis of cylindrical specimen and slope infiltration process. The results show that the change of saturation is one of the important factors causing the deformation of rock mass during the transition from unsaturated seepage to saturated seepage. The research results have important guiding significance for revealing the abnormal deformation mechanism of the dam and the mountain in the early stage of the storage of the super high arch dam.

When multi-laminated thin formation is fractured as a whole，it is hard to know fracture initiation and propagation morphology because of stress contrast，lithology difference，interfacial property and some other factors. In this paper，a model of three-layer hydraulic fracturing was designed and an improved large-scale tri-axial fracturing device was used to observe the fracture initiation and propagation. The effects of rock strength and interfacial property on the hydraulic fracture initiation and propagation were studied. It was observed from the experimental results that an unbonded and smooth interface inside rocks would induce a shear slippage at a low fracturing pressure under overburden pressure of 10 MPa. And the fracture would firstly be induced from a layer of low rock strength and then turned to propagate through the weak bonded interface when interlayer cement strength was small. However，large interlayer cement strength would cause sequential fracturing in all layers with low strength layer fractured first. In addition，asymmetric distribution of fracturing fluid in fracture was observed directly.

Complex geological condition and excavation in deep tunnel frequently led to collapse accidents，which seriously threatened the safety of life and property of workers on site. In order to reduce the impact of collapse on the Neelum-Jhelum project in Pakistan，a microseismic monitoring system was constructed to study the temporal and spatial evolution law of the microseismic activity during the development of collapse. The research showed that，when the working face was gradually approaching but didn′t reveal rock mass in the collapse zone，fewer microseismic events occurred，and the cumulative released energy increased rapidly. The cumulative apparent volume grew slowly and the energy index was basically stable after sudden increase. As rock mass in the collapse zone being revealed by excavation，more microseismic events occurred. The cumulative released energy increased slowly，the cumulative apparent volume sharply increased，and the energy index suddenly decreased. Microseismic events clustered in a certain part of collapse zone，where an interface filled with calcite developed. Most of the microseismic events occurred within the 3 times of the tunnel radius from the cavern wall in surrounding rock.  The mechanism of rock cracks in the collapse zone was “shearing at the first and tensioning in the end”. The development of collapse showed obvious stage characteristics：the interface filled with calcite slide→parallel tensile cracks occurred in surrounding rock after revealed→The cantilever rock beam cracked on the end→The cracks penetrated and the rock blocks fell by gravity.

Blasting excavation of the rock slope produces geometry changes which will induce stress redistribution within the rock mass. The stress redistribution can be reflected by the apparent stress of micoseismic(MS) events. The apparent stress of MS events increases along with the seismic moment and radiated energy. High apparent stress in rock mass can reflect the disturbance degree subjected to intense blasting excavation. The distribution characteristics of high MS apparent stress in the left bank slope can delineate the main damage regions，which is in good agreement with the result of numerical simulation using the Realistic Failure Process Analysis code in three-dimension(RFPA^3D). The period that the average daily apparent stress reduces strongly and the cumulative apparent volume increases can be regarded as the precursor of the deformation of rock slope. The present achievements can provide some references for the stability evaluation of similar high rock slopes based on microseismic monitoring.

The compliance of a drilling-rod hydraulic fracturing test system has severe impacts on the calculation precision of the maximum horizontal principal stresses. How to improve the accuracy of deep hole hydraulic fracturing test has always been a hot topic and tough task in this field. In order to determine the in-situ stress state in a borehole of ZJGTEST-ZK 10 of 600 m deep，close to the Zijingguan fault in the Yi County，Hebei Province，Brazilian disk tests，hollow cylinder hydro-fracturing test，and concentric annular core tension test were conducted so as to determine the tensile strength of rock cores，and the tensile strength of granite cores ranges from 6.42 MPa to 9.35 MPa. The average tensile strength determined by the in-situ hydraulic fracturing test was 8.01 MPa，which was consistent with those determined by the above three laboratory tests. Based on the ten successful in-situ hydraulic fracturing tests and three laboratory tests，final determined maximum horizontal principal stresses range from 17.70 MPa to 35.38 MPa，the measured minimum horizontal principal stresses range from 10.36 MPa to 19.38 MPa，and the estimated vertical principal stresses range from 5.82 MPa to 15.49 MPa，the orientation of the maximum horizontal principal stress is NE，and ranges from NE40° to NE56°. The stress state is stable，and favorable for thrust faulting. By comparing the maximum horizontal principal stress magnitudes based on different tensile strengths and reopening pressures，the maximum horizontal principal stresses based on tensile strengths are markedly greater than those based on reopening pressures due to the negative impacts from the test system compliance when the test interval is deeper than 440 m. For the deeper test intervals，the maximum horizontal principal stresses based on tensile strengths indicate true in-situ stress state.

Considering that displacement monitoring index of concrete dam is affected by the sensitivity of structural monitoring time series and performance degradation，in order to improve the reliability of the displacement monitoring index on the early-warning function for safety behavior of concrete dam service，a method for determining displacement monitoring index of concrete dam based on the hybrid model considering parameter interval inversion modification is carried out on the combination of interval analysis theory，rough theory and neural network theory in the paper. The hybrid model with the function of interval parameter inversion is established on the basis of dam prototype monitoring data，which combines rough theory and neural network theory. The material parameter intervals of concrete dam and bedrock are inversed by the model. Concrete dam displacement monitoring index is determined by the most unfavorable combination of parameters inversed by interval inversion. Examples show that the method combines the uncertain data excavation ability of rough theory and self-learning ability on nonlinear problem of neural network，it has good robustness. Material parameter intervals of concrete dam inversed by the method are reasonable and effective，the monitoring index carried out by the method provides a theoretical basis and decision support for long service and operation management of concrete dam. In addition，the method can be used for determining displacement monitoring indexes of other structures after some expansion and improvement.

At present，the research on the deformation and damage evolution mechanism of tunnel structures under the action of loose load is relatively scarce，and the quantitative analysis of structural residual bearing capacity is lacking，which is not conducive to of structural health assessment and the determination of maintenance treatment program. For these problems，this paper studied the deformation regularity and damage characteristics of the structure under different surrounding rock conditions，summarized the key indexes of structural health assessment， established the standard of health classification based on bearing capacity through indoor model test and finite element analysis software. Through these researches，we can draw the following conclusions. (1) The failure process of the lining is divided into three stages，the arch cracking and the main crack opening as the dividing line. The inner side of the vault and the outside of the arch pull the steel bar apart，the structure turned into three-hinged arch at the same time. (2) Arch crown settlement is 3.3 cm with resistance coefficient 1.58 MPa/m and 0.23 cm with resistance coefficient 200 MPa/m under the same load of 100 kPa. Resistance coefficient increases from 1.58 MPa/m to 200 MPa/m，the ultimate bearing capacity increases from 196 kPa to 1 840 kPa. (3) Through taking lining cracking，crown sinking 3 cm，arch crown steel yield，arch haunch steel yield and arch crown steel breaking as key nodes，and taking crown settlement and side wall convergence as simple evaluation indexes，the 5 grade criterion of lining structure health degree is established. The control value of crown settlement for V–VI grade surrounding rock is suggested to take 5 cm.

This paper focuses on these problems which are serious waste of resources in super-long two-entry longwall panel，supporting difficultly and suffering power disaster because of jumping mining. In the study，the invention patent“Sequential extraction technology for super-long two-entry longwall panels”firstly proposed，which indicates that it needs to give the suitable parameters including the sizes of the big coal pillar and the small coal pillar，the delayed distance of the gob-side gateroad heading to the working face of the initial panel and the advanced distance of the heading to the working face of the successive panel in engineering practice. Using theoretical analysis and field measurement，the method determining the above parameters and the precise data are gived by combining with the actual engineering background. Next，comparing with original support scheme and parameters，the deformation of the gateroad along gob-side with new technology becomes small by field measurements，which not only meets the need but also creates 880 million yuan of economic benefits in single panel. The results of the study can further provide engineering basis for the mine with the coal seam #5 of 5.7 m thickness and 5 200 m long and similar geological and mining conditions.

During drilling and blasting excavation of deep tunnel，high and low dual-frequency band vibration generated by coupling action of blasting load and transient unloading of in-situ stress will endanger safety of adjacent buildings，but low-frequency amplification effect of transient unloading of in-situ stress is usually ignored in traditional vibration safety evaluation. Firstly，excavation of main underground powerhouse in Pubugou hydropower station as background，vibration spectrum characteristics of hole and adjacent tunnel under coupling action of blasting load and transient unloading were studied by time-energy density，amplitude spectrum and filter analysis method. Then，based on dynamic response analysis of structure，low-frequency amplification effect of transient unloading induced vibration hidden in coupling vibration waveform was discussed. Finally，combined with double index of peak value of particle vibration and vibration frequency，safety of tunnel blasting excavation surrounding rock was evaluated. The results showed that peak value of vibration caused by blasting load is obviously larger than that induced by transient unloading of in-situ stress in hole，distribution law is opposite in adjacent tunnel. Vibration produced by blasting load is mainly high frequency，main frequency range 65–135 Hz，with an average frequency of 96 Hz，but vibration induced by transient unloading is mainly low frequency，main frequency range 20–60 Hz，with an average frequency of 46 Hz. Frequency of transient unloading induced vibration is lower and closer to granite natural frequency of 37 Hz，it is easy to produce resonance，the amplitude magnification reaches 1.72. When in-situ stress level is higher，reaching 70 MPa magnitude，low-frequency amplification effect of transient unloading of in-situ stress results in unsafe zone of surrounding rock expanding significantly from 6.0 m to 20.1 m. The research results can provide a reference for vibration safety evaluation of deep tunnel blasting excavation.

The constant valley shrinkage deformation of the Xiluodu arch dam occurs after water storage，and the valley deformation does not converge at present，which has a great influence on the local stability and overall stability of project. By analysing the geological conditions and in-situ deformation data after impounding，the mechanism of valley shrinkage deformation of Xiluodu arch dam is revealed. The seepage field and inclination of interlayers control the deformation characteristic. An elastic-viscoelastic-viscoplastic nonlinear creep model considering effect of pore pressure on spherical stress tensor and yield surface is proposed to analyse the valley deformation. Based on the monitoring data of deformation at early stage of water storage，the creep parameters of rock mass are back analysis，which is adopted to predict the trend of shrinkage deformation and the effect on dam safety. After back analysis，the numerical results of the normal water level agree well with the monitoring data，and the deformation process of the valley is simulated exactly. After ten years，the slope deformation tends to converge，but the overall deformation value is large，and the extrusion on dam abutment is severe，which need to be paid more attention.

In order to analyze the action mechanism of tunnel support structure and its supporting characteristics in layered and weak rock tunnel，indoor physical simulation test and steel-concrete composite beam of the three point bending tests were conducted successively，and the mechanical and deformation characteristics of common screw bolt and steel pipe anchorage of rock under uniaxial compression tests and the steel arch bending performance were researched. The test results show that，the bolt mainly achieves the anchoring effect by improving the stress state of surrounding rock and improving the strength of surrounding rock，and also the improvement of strength to anchorage surrounding rock is mainly the effect of compression zone of pre stress，the repairing effect of anchorage agent on surrounding rock and the strengthening effect of anchor rod on the whole strength and density of anchor. Through the CT scanning of the anchor specimens after the test，it is found that the crack arresting effect of the anchor on the crack is the result of the weakening，shear and stop of the crack in the anchorage zone，and the crack arrest effect is related to the size of anchorage zone. The larger the anchorage zone is，the better the crack arrest effect is. According to the different characteristics of bolt and anchor roll steel pipes，explosive bolts can anchorage layered shale tunnel lithology good，while the function of grouting steel pipe is more suitable for the poor lithology of the soft fractured rock mass.

anical test system and PCI–2 acoustic emission system. A damage evolution model of Beishan granite based on the cumulative ring counting rate of acoustic emission under triaxial compression was established. Its damage characteristics and damage evolution law were analyzed. The results of the show that：(1) The Beishan granite under the condition of conventional triaxial compression，both mechanical parameters and the acoustic emission parameters show obvious confining pressure effect. Properly increasing the initial confining pressure is an effective way to promote the rapid closure of pre-existing fissures and to prevent the formation and development of new fissures. (2) Through the analysis of the stress-time-acoustic emission parameter curve，it is found that different periods of sound emission ringing counting rate and the five stages of the accumulative number of energy have a good correspondence with the five stages of rock compression deformation. (3) The damage evolution process is divided into damage formation stage，damage stable growth stage，accelerated damage growth stage and damage stage. It can reasonably reflect the deformation and failure characteristics of Beishan granite under different confining pressure and different facture stages.

For the anchor cables of operation period in engineering，periodic fluctuation of cable load is closely related to temperature and other seasonal factors. The monitoring data of anchor cables in the high slope of permanent shiplock is uesd to build an ARDL model and simulate the fluctuation of cable load after the steps of using temperature as a main variable，analyzing the reasons for prestress change caused by temperature，finding the logs and using PCA to eliminate multicollinearity between lagged variables. The results show that temperature has a significant effect on anchor cable prestress. Finally，the validity of this model is verified by comparing predicted values with measured values. The long-termed process of prestress change caused by temperature has also been discussed.  

To meet the IEA¢s(International Energy Agency) proposed minimum 90d¢s petroleum reserve，a large number of water-sealing petroleum strategic reserves are required due to safety. However，there are few researches on balance analysis between grouting and water seal in underground petroleum storage caverns at present. A series of studies are carried out to analyse grouting balance based on Jinzhou state reserve projects in this paper. Computational algorithm of penetration length of grout in fracture network with pipe network model is developed. Here，grout is regarded as Bingham fluid. Then，grouting intensity number(GIN) method for underground petroleum storage is developed to achieve a balanced water-grout state. Parameters selection algorithm for GIN is also developed then. Next，five GIN numbers are selected for four storage caverns in Jinzhou with GIN curve computing method proposed in this study，which avoids fracture splitting and excessive grout loss. Finally，six grouting routes of tested points fit well with GIN envelope curve.

Taking west area of Chengchao iron mine as background engineering. According to the analysis of geological survey and the monitoring results from horizontal displacement and subsidence displacement in the west area of Chengchao Iron mine，and combining with approaches of drill-hole monitoring in goaf roof and high-density electrical prospecting in cave region，then the roof collapse characteristics and the ground collapse mechanism are analyzed，besides the law of surface deformation after ground collapse. The research results indicate that the process of goaf roof collapse is intermittent，and whole sinking occurs when the goaf roof collapse spreads upwards to gypsum stratum. Large amounts of groundwater are deposited in rock fractures and karst caves due to the aquiclude of gypsum，which has great influence on surface subsidence in preliminary stage of mining. High-density electrical prospecting results prove that the essential reason to the surface collapse is the rapid increased negative pressure generated by fast dewatering after gypsum stratum collapsed. Under the action of this mechanism，the location of surface collapse may be either right above the mined-out or near the mined-out boundary. Surface deformation extends outward with funnel-shaped tendency，and the displacements increasing timing of measuring points corresponds to the proceeding of underground mining well，showing that rock disturbance caused by underground mining has already extended to surface and ground collapse is controlled by the underground mining.

With the development of deep underground space and deep energy exploitation，more and more attention has been paid to the in-situ stress measurement technology of deep rock mass. The testing environment of high temperature and high pressure in deep rock mass is the key to restrict the development of this technology. In this paper，a new micro-optical borehole deformation measurement method with multi probes type is proposed and the corresponding measurement apparatus is developed. With the structure design of the rigid probe and the independent packaging optical measuring device，the system is conducted to solve the problem of the complex high temperature and high pressure environment. In the measurement of the borehole wall deformation，the design scheme of the structure by using the multi probes and the micro optical photography technique for the visualization of the small change of the borehole wall is presented. The system realizes the synchronous acquisition of multiple sets of borehole deformation data with more abundant effective data and higher measuring efficiency. Based on the features of the system，the method of borehole shape measurement is put forward，which breaks through the fixed thinking mode which can only measure the diameter deformation for a long time. It lays the foundation for the new method of in-situ stress measurement based on borehole shape. Through simulation experiments，the feasibility of the principle of the system，the rationality of the structural design，the correctness of the measurement method and the operability of the practical application are verified. Through the study of micro-optical borehole deformation measuring system，a number of key issues including design，principle and method will be solved. A novel measuring device for measuring the deformation of borehole diameter and the shape of borehole is developed providing a new testing technique and method for the in-situ stress measurement in deep borehole.

Inertia force and dynamic earth pressure have remarkable influence on the stability of reinforced soil retaining walls under dynamic loading. Although the existing calculation methods provide rules and suggestions for calculation of the dynamic earth pressure of reinforced soil retaining walls under dynamic loading，a large number of engineering practices show that the methods are excessively conservative and they are distinctly different from each other. In order to study the dynamic earth pressure of reinforced soil retaining walls under dynamic loading，a shaking table model test was carried out by harmonic wave loading. According to the time history of values recorded during the test， similarities and differences between values tested and calculated by the current methods were analyzed. The following conclusions have been obtained：because when the earth pressure reaches peak values，the wall facing moves back to the fillings，so the peak values cannot be directly used to analyze the active failure of the wall under dynamic loading；the inertial force and the dynamic earth pressure do not reach peak values at the same time，and there is a phase difference between them；the distribution of the earth pressure along the wall height and its height of interaction point are similar to the M-O method and the S-W method respectively，and the test value is much smaller than the value calculated by the above methods；when the wall reaches a active state，the earth pressure at the end of reinforcements is negative，so the earth pressure is smaller than that without dynamic loading.

The rising of the capillary water in the saline soil foundation will inevitably lead to the upward migration and aggregation of salinity in the soil. The characteristics of the water and salt migration in saline soil were simulated by the test of the capillary water rising under the natural conditions. The changes of water content，Cl^－and  at different times were measured after the gradient migration，and the characteristics of the capillary water and salt migration between the compacted saline soil and sulphate saline soil solidified by lime fly ash water glass were compared under the distilled water and compound salt solution. The results show that the rates of the capillary migration and Cl^－and  migration in the solidified saline saline soil are less than those in the compacted saline soil，which indicates that the solidified soil has the effect on slowing down the rising of the capillary water and hindering the salt migration. After the stabilization of capillary water migration，the water content of the compacted soil decreases linearly and the water content in the solidified soil decreases linearly first and then stay the same along the height，indicating that the solidified soil has a stable water-holding ability. During the migration process，the migration rules of the water content，Cl^－ and  are consistent and the migration rate of Cl^－ is greater than that of . The experiments show that the solidified sulphate saline soil not only has an improvement of strength，but also can block the upward migration of salinity especially the upward migration of sulphate ion.

There is a deep soft soil under the immersed tube foundation of the Hong Kong-Zhuhai-Macau Bridge (HZMB) island-tunnel joint part. In order to make the foundation stiffness smooth transition at the position，the sand compaction pile(SCP) method was adopted for its no pollution and speedy construction compared with some other treatment methods such as offshore cement deep mixing(CDM) or gravel compaction pile(GCP). This goal will be achieved by controlling the SCP area replacement rate. In this paper，the design basis and the specific design parameters are given and verified by the in situ loading test. Better settlement data was obtained by the application of liquid pressure settlement sensor at the loading process. The three - point method，the hyperbol-ic method and the Asaoka method are employed to predict the ultimate settlement of the foundation. The result predicted by the three method were discussed with the calculation results proposed by Aboshi. It was showed that the in-situ load verification method is directly effective. It can be used as an auxiliary method for the analysis of important engineering foundations. The results obtained by these prediction methods are basic equivalent whereas the results obtained by the hyperbolic method are slightly larger than the other two method. It should be selected a larger time in-thermal as much as possible to get the preferable results when the three-point method was adopted. For the high displacement rate compacted sand piles，the results calculated by the empirical formula proposed by Aboshi are significantly larger than the test results whereas they are very closed to the results calculated by the same formula with the low area replace ratio. The study is expected to provide some reference meaning for the SCP design and in situ test techniques.

The unignorable volume plastic strain and irreversible shear strain would be produced due to the rotation of the principle stress axes. The process of rotation of principle stress axes is decomposed in order to explore the causes of the rotation of the principle stress axes. The step for rotation of principle stress axes is divided into a process that the superposition of self rotation to XYZ axes in physical space. The relationship between rotation angle of principle stress axes and arctangent value of ratio between shear stress and normal stress in Mohr¢s circle is established. The rotation process around single axes for cubical unit is analyzed in physical space. The pure rotation of principle stress axes in cyclic loading condition and round-trip loading condition and conventional triaxial compression condition are modeled by using the proposed incremental model. The simulation result has been shown that it is effective to use the proposed model to predict the deformation of geomaterials under rotation of principle stress axes condition.

Tidal load is fitted by trigonometric function，and One-dimensional nonlinear consolidation settlement of layered soils is calculated under tidal load. Based on the tidal load and the result of subsurface settlement，Winkler foundation model is used to calculated equivalent subgrade coefficient at different time. Considering the effect of joint，an element-joint model is built to analyze the vertical displacement of immersed tunnel elements under tidal load. Rely on Yongjiang Immersed Tunnel in Ningbo，the vertical displacement of joints and the midpoint of the elements is calculated under tidal load，and the theoretical results are compared with the measured results. The study shows that the calculated vertical displacements of Joint 2 are consistent with the monitoring data. It provides validation of the proposed method. The range of vertical displacement amplitude of Yongjiang Immersed Tunnel¢s elements is 4–8 mm under tidal load. The maximum displacement amplitude is present to the midpoint of Element 3. The displacement amplitude of Element 3 in a day and in a year reaches 6.9 mm and 7.4 mm respectively. As for one section of an element，its displacement amplitude in a day is slightly larger than that in a year，and they are positively correlated in different sections. As for one element，its displacement amplitude of midpoint is larger than that of joints. As for the same position of different elements，the closer to the midpoint of tunnel the section is，the lager the displacement amplitude is.

ll of soilbags. The results show that the retaining wall of soilbags dissipated a lot of vibration energy during the earthquake due to its relative flexibility. The acceleration amplification coefficient increases with the wall height，and decreases with the increasing input vibration amplitudes. The natural frequency and the spectral characteristics of the soilbags¢ retaining wall are similar to those of the backfill soil，so that the retaining wall can deform basically together with the backfill soil. The natural frequency of the retaining wall model decreases with the increasing input vibration amplitudes and the increasing vibration number. The peak dynamic earth pressure between the retaining wall and the backfill soil increases with the increasing input vibration amplitudes，and it approximately takes an“S-shape”distribution(or called double peaks) along the wall height. The cumulative lateral residual displacement of the retaining wall model of soilbags is small when subjected to multiple vibrations. The maximum ratio of the cumulative displacement to the wall height is about 0.29% at the input earthquake acceleration of 0.6 g，indicating the good seismic behavior of the retaining wall of soilbags.

In order to serve the pile foundation designs in China-Maldives Friendship Bridge construction project, and investigate the end bearing characteristics of rock-socketed pile in coral reef limestone, indoor mechanical tests and end bearing pile model tests were carried out on the reef limestone cores drilling from the bridge foundation position. By these means，the strength and failure law of reef limestone samples under three direction compression in the pile end are obtained. Experiment results show that the pile end stress are obviously higher than the uniaxial compression strength，and greatly influenced by specimen structure and strength. In different structure specimens，the pile end stress curve are in different growth trend with pile top displacement. In the processing of test results, we determined the vertical compressive ultimate bearing capacity of single pile in different structure specimens according to the technical code for testing of building foundation piles(JGJ106—2014). Considering the influence of diameter scale between actual pile and model test，the design reference of ultimate end bearing value in different structure types of reef limestone are determined after reduction associate with in-situ pile test result.

The continuous development of urban construction leads to less and less available underground space and promotes the rapid development of the novel tunneling technologies，such as special-section shield tunneling. It has become an important issue to study the corresponding method of predicting soil displacement induced by tunneling. The analogous stochastic medium theory method(ASMTM) has been presented through introducing the idea of the stochastic medium theory method(SMTM) to Loganathan¢s solution，and the general formula of ASMTM has been derived. Taking the single circular tunneling and the double-O-tube(DOT) shield tunneling as examples，their expressions to predict soil displacement induced by tunneling have been given first，the ASMTM then has been verified and applied in some cases，comparing with the SMTM，Loganathan¢s solution and the observed values. The results show that the single circular tunneling-induced soil displacements predicted by the ASMTM are closer to the observed values than those resulted from the SMTM and Loganathan’s solution. For the DOT shield tunneling，the predicted soil displacements from the ASMTM are in good agreement with the observed values，and the soils above the left and right tunnels have the maximum displacement. The presented ASMTM can be used to prediction soil displacement induced by arbitrary shaped-section tunneling and has an extent area to use，with a sufficient reliability. This study provides an important theoretical basis for prediction soil displacements induced by special-section tunnel construction.

With the large-scale construction of high-speed railway in Western China，the proportion of tunnels in the line is getting higher and higher. At the same time，the disease caused by landslide is more and more serious during operation. However，there is no uniform standard in the design of tunnel in landslide area in China，and there is no complete calculation theory. Therefore，this paper takes the tunnel under the orthogonal system as the object of study， and through the investigation，induction and summary of the disease characteristics of the tunnel lining in the engineering example，the corresponding engineering geological model is finally established. By using the classical soil mechanics method，the vertical component of the thrust behind the slide of the tunnel is regarded as the vertical distributed load acting on the slip zone. The additional load generated by the tunnel arch is calculated by using the method of the Boussinesq J and the horizontal component is distributed on the sliding surface as the uniformly distributed load，and the Cerruti V method is used to calculate the horizontal additional load on the side wall of the tunnel. Based on the compressive strength and the Loose circle theory of tunnel，the minimum depth of tunnel under the sliding surface is calculated. Then the model test is used to verify the method and the results show that the calculation method of the additional load is in line with the engineering practice，and can provide reference for the design of the tunnel in the landslide area.

Accurately understand the changing rules of hydration kinetic process and hydration mechanism of fly ash paste filling materials will help to analyze the reasons for the low early strength，large deformation and severe bleeding，and then to control the formation process of the filling material structure，as well as to give a reasonable process parameters. In this study，the micro heat flow and hydration heat of fly ash paste filling materials were tested by used TAM Air Isothermal Calorimater. The hydration kinetics parameters were calculated based on Krstulovi?–Dabi? model. The characteristics of hydration kinetic process at different stages were analyzed. The cement hydration modeling software was used to simulate the hydration process of filling materials under different degree of hydration and the hydration mechanism of fly ash paste filling materials was further discussed. The results showed that the hydration kinetic process of fly ash paste filling materials can be described by three processes：nucleation and crystal growth(NG)，interactions at the phase boundaries (I) and diffusion (D). NG process dominates in the early stage of hydration，I process and D process becomes the dominating factor gradually as the hydration degree increases. Compared with cement，the hydration kinetic process change requires a higher degree of hydration when the mixture of fly ash and coal gangue. The simulation of degree of hydration results provided a useful reference for describing and discussing the hydration characteristics and microstructure evolution. Through the description of hydration mechanism of fly ash paste filling material，the general rules of filling material structure and its forming process are clarified. The results are instructive to promote the research and development of fly ash paste filling materials.

Considering the space effect，the general deformation mode of subway station foundation pit in sandy cobble stratum is acquired based on a large number of measured deformation data from 18 subway station foundation pits in Beijing. By establishing the relationship of the maximum deformation between any section at different distances(d) from the corner and the section in the middle，it shows that the general deformation rules can be expressed piecewise by Guassian Function based on the different ratio of length(L) to depth(H_e) and the type of pit support structure. And it can also determine the position of the maximum deformation section. On the basis of the general deformation mode，which is concluded by summarizing the above deformation rules，the foundation pit can be divided into the corner effect area and the plane strain area quantitatively. Based on this，the dynamic deformation control process can fully consider the space effect during the stage of design，construction and monitoring，and it can control the deformation economically and effectively.

The amount and scale of engineering construction in Xinjiang develop greatly in recent years. Engineering practice necessitates that a comprehensive understanding on the reconstituted loess¢s mechanical behavior to provide theoretical support. In this research，laboratory tests were performed using an infilled loess material from a channel slope in Xinjiang，to investigate the dilatancy and instability of the material which are affected by the degree of compaction. Scanning electron microscope technique and CT technique were used firstly to examine the microscopic and mesoscopic compositions firstly. The stress-strain relationship，the dilatancy and the experienced paths were then analyzed under saturated undrained condition，with consideration of three levels of degree of compaction and three stress levels. Thereafter，the results are compared and verified under drained condition. The findings are below. Firstly，the material could demonstrate contraction-dilation-contraction behavior，between the contractive behavior at loose state and the dilative behavior at dense state. Secondly，the material has a unique critical state line in the stress plane，while its critical states are affected by initial void ratio，suggesting a belt region in the compression plane. Third，the slope of instability line increases with the degree of compaction，indicating a higher stress ratio to achieve instability region. Therefore potential instability led by engineering disturbance reduces at a higher degree of compaction.