By adding cushions with designed oblique surfaces to MTS system and to split Hopkinson pressure bar(SHPB) device，a series of experiments were conducted to investigate the quasi static(strain rate 3?10－5 s－1) and dynamic(strain rate 50 and 100 s－1) responses of Shandong granite under combined compression-shear loading. Five oblique angles，i.e. 0°，15°，30°，45°and 60°，were investigated in the present study. The results showed that both normal and shear modules exhibited the strain rate effect and certain path-load dependency，which revealed the coupled compression-shear effect. The normal modulus was the most sensitive to the shear stress. The failure strength of granite exhibited strain rate effect and path-load dependency. Employing the Drucker-Prager(D-P) criterion model to simulate the failure surfaces of Shandong granite at different loading rates，the strain rate effects of strength parameters，e.g. the inner friction angle and inner cohesion，were analyzed. Digital imaging correlation(DIC) method was employed to systematically analyze the displacement field and strain field. The results showed that the process of dynamic compression and shear loading was controlled by the shear strain. For the rock specimens were compressed from quasi static loading to dynamic loading，the main cause of specimen deformation and failure were turned from the tensile strain to shear strain. All these were resulted from the non-uniformity of rock specimen.

This paper describes the numerical modeling of excavation damaged zone(EDZ) in surrounding rocks with embedded structural planes. A modified rigid body spring method(RBSM) was proposed to simulate the initiation and propagation of micro cracks. Both the tensile and shear failures were considered by introducing a failure criterion which combines the Hoek-Brown criterion and the tensile strength criterion. The rock material was represented by an equivalent discrete assembly of rigid blocks based on a degradation Voronoi mesh. A simple case was employed to demonstrate the validity of the proposed model，and the simulation results were compared with ones from the finite element method. At last，the EDZ of the diversion tunnel in the Jinping II hydropower project was studied using the proposed model with the emphasis on the NWW joint and some suggestions were given on the reinforcement project. The simulated EDZs were generally in agreement with the in-situ observation.

Due to the developed columnar joints in basalt III1 around the diversion tunnel at Baihetan Hydropower Station along the Jinsha River，the relaxation and failure of basalt with columnar joints during the excavation had the severe influence on the personnel and construction progress. Microseismic monitoring technology was utilized during the excavation of columnar jointed basalt. Along the tunnel，the microseismic activity in columnar jointed basalt was found to obey the Logistic(3P) distribution. Three typical microseismic activity zones in columnar jointed basalt along the tunnel near the working face were obtained，i.e.，a strong unloading area，a comprehensively influenced area and a time relaxation effect area. Rock bolting should be completed in the strong unloading area. In the period of working face around the researched area，the fractures developed rapidly into the inner rockmass. When the working face was far away，the microseismic activity in the sidewall was weak. Meanwhile，the area of micro-fracture concentration stabilized in the ranges of 6 meters in sidewall finally. A low excavation rate weakened the influence of unloading of excavation on columnar jointed basalt.

In order to quantitatively study the crack development of siltstone under triaxial compression using CT numbers，a damage partition method was proposed based on the theory of damage and the CT data in this study. The CT scanning section of the rock was divided into the complete zone( )，the damaged zone( ) and the hole or crack zone( ). The porosity，the damage rate，the degree of integrity of the rock were defined. The damage development of the siltstone CT test process under triaxial compression was analysed. Using this method，the role of each set of CT data in CT scanning was fully played，the damage and strain localization of the rock under loading be studied quantitatively. Only when the sample reached a high degree of damage under the confining pressure，the mesoscopic fracture cracks were developed into the macroscopic cracks，and the failure occurred，which was the reason of the increasing of rock strength and plasticity. The fracturing cracks on both ends of the specimen appeared late，and the specimen failed suddenly. The fracturing cracks of the scanning section were mainly distributed on the outer circular areas，while the fracturing cracks on middle of the specimen appeared early，had a longer expansion process，and the fracture cracks were across the scanning section.

To investigate the degradation of rock microstructure under static and dynamic loads，split Hopkinson pressure bar(SHPB) tests of granite specimens with a pre-existing opening under various axial pre-stresses and the same dynamic load were conducted. The crosswise relaxation time T2 distribution，porosity and nuclear magnetic resonance images were obtained with the nuclear magnetic resonance(NMR) technique. The peak spectrum of T2，the spectral area and the porosity of the granite specimens subjected to the dynamic loading all increased with the increase of static axial pre-stress. The degradation of granite under static-dynamic loads was more sensitive when the static pre-stress exceeded 10 MPa. The NMR results of specimens with the circular opening and ones with the square opening were compared. The damage of the specimen with the square opening was severer than that with the circular opening，and this phenomenon was more pronounced when the static pre-stress exceeded 10 MPa. The NMR images yielded the straightforward demonstration of the damage degradation process of pore structure of granite under static-dynamic loads.

Split Hopkinson pressure bar(SHPB) apparatus was adopted to investigate the effect of the contact area of rock joints on stress wave propagation in this study. The research focused on two aspects，the dynamic property of joints with different contact areas and the stress wave propagation across joints with different contact distribution forms. Each sample was made of two rock blocks，one with an artificial cut surface. A series of tests were carried out and it was found that the impact velocity，the contact area ratio and the relative intensity degree of joint surface area apparently affected the dynamic stress-strain relation of rock masses and the stress wave propagation across rock masses. The transmission coefficient increased with the increase of contact area ratio of joints and the impact velocity. The transmission coefficient of the joints with a small and dispersed contact area was higher than that with a large and clustered contact area.

The influence of freezing-thawing cycles and unloading effect in slope engineering were investigated in the excavation of rock in the cold region. Experiments of uniaxial and triaxial compression and triaxial confining pressure unloading were carried out to the sandstone samples experienced different freezing-thawing cycles. The peak strength and the elastic modulus of rock were found to decrease gradually with the increase of the freezing-thawing cycles. The radial strain and the volume strain were changed greatly but the axial strain variation was relatively small under the same decrement of confining pressure. The greater the freezing-thawing damage was，the more sensitive of the radial and volume strains to the decrement of confining pressure. The deformation modulus of rock decreased gradually in the process of confining pressure unloading. With the increase of the freezing-thawing cycles，the reduction rate of the deformation modulus and initial deformation modulus decreased. Poisson?s ratio was gradually increased during the unloading of confining pressure. With the increase of freezing-thawing cycles，the growth rate of Poisson?s ratio decreased. The relationship between the increase of Poisson's ratio in the initial stage and the volume strain was approximately linear. The failure pattern of rock under different freezing-thawing cycles in uniaxial compression test was splitting failure and in conventional triaxial compression test was shear failure. The shear zone was developed roughly along the diagonal of the rock end face. This phenomenon was accompanied by the rock fall off. The failure mode in triaxial confining pressure unloading test before peak failure was the mixture of those in the uniaxial and triaxial compression tests.

Triaxial creep and elastic aftereffect tests to the sandstone specimens from the Three Gorges reservoir area were carried out with the creep testing machine of rock. The creep and elastic aftereffect deformation curves under different pressures were acquired. The rock specimens exhibited the time-dependent deformation characteristics. The creep curves had the typical three stages of rock creep. The magnitude and the rate of the time-dependent deformations gradually increased with the increasing of the pressure. The creep and the irreversible deformation were similar. The creep model of Burgers and the constitutive equation of the elastic aftereffect under the three-dimensional stress state were deduced. The parameters of the triaxial creep and elastic aftereffect models were obtained from the test data calculated with an optimized algorithm. The time-dependent parameters were nonlinearly reduced gradually with the increase of the stress levels. When the sandstone was in the stage of creep，the parameter of viscosity reflected the steady state of creep deformation of rock specimen. When the sandstone was in the stage of aftereffect，the parameter of viscosity described the variation of irreversible deformation after creeping.

In order to study the interaction between the blast-induced cracks and an empty hole under blasting load in notched boreholes，the blast-induced crack initiation and propagation in PMMA material with a circular empty hole under blasting load was studied with the digital laser dynamic caustics experimental system. During a simple borehole blasting，the blast-induced crack from a notched borehole B had a straight path，directly met the empty hole in the propagating process，was mostly in the tension stress field and grew as mode I. In the simultaneous blasting with two notched boreholes，the interaction between the empty hole and the main blast-induced cracks affected the main blast-induced crack propagation，and the two main blast-induced cracks were respectively coalesced with two blast-induced wing cracks. The propagation speed and dynamic stress intensity factor were reduced with the interaction between the compressive stress waves of P waves in explosive stress waves and the propagating cracks.

Specimens with different angles of pre-existing fissures were made using the high-strength gypsum. The anchoring effect of the pre-stressed bolt on crack prevention was studied under uniaxial compression. The results showed that the elastic modulus，the crack initiation strength，the peak strength and the residual strength of anchored specimens increased to certain extent and increased with the increase of the pre-stress in bolt. The anchoring effect with the angle of 45 degree was more obvious than that of 30 degree and 60 degree. The pre-stressed bolt not only effectively restrained the separation of the failure planes of wing crack but also changed the expansion modes of the secondary crack. The change of the axial stress of bolt during the deformation of specimens was divided into four stages：the slow growth stage，the rapid growth stage，the sharp rising stage and the decelerated growth stage. The peak value of axial stress increased with the improvement of pre-stress of bolt. The anchoring mechanisms were analyzed with the theory of fracture mechanics. The role of the pre-stressed bolt played before peak strength was axial pressure and after peak strength was a combination of anti-shearing and axial pressure.

The mechanical model and parameters of rock is the basis of calculating the stability of soft rock tunnel. A visco-elastic-plastic softening model for the long-term stability analysis was established through the experiments，theoretical analysis and empirical analogy on the long-term strength of mudstone. The artificial intelligence method was used to investigate the experimental and monitored data from a project and the values of the rheological parameters of rock were obtained. The rheological model and the experimental flow curve fit well. The prediction of the long-term stability of a large-span tunnel was made. The forces in the bolt and lining were found to vary similarly to the creep characteristics of rock. The stress was increased in the initial phase，and the stress in lining was essentially unchanged after 3–5 years and the supporting structure was safe.

The creeping problems of argillaceous slate in the construction period of Yaojia Tunnel at Changsha—Kunming(Hunan) Section of Shanghai—Kunming Passenger Railway Line were investigated. The influence of stress state and rate of water absorption on the creeping properties of argillaceous slate were analyzed with the creeping tests under triaxial compression. A water degradation factor was introduced based on the Burgers constitutive model of creeping and a visco-elasto-plastic constitutive equation for creeping considering the rate of water absorption of argillaceous slate was established. The rationality of constitutive equation for creeping was verified with the software ANSYS using prony series transformation. With the increase of the rate of water absorption，the creeping deformation and creeping rate of argillaceous slate were increased and the process of entering the constant rate and accelerated creeping stages were speeded up. The increasing of stress difference meant that the process of entering the constant rate and accelerated creeping stages were speeded up and the time length was shortened. With the increase of water absorption rate，the creeping parameters(deformation modulus，viscosity coefficient，bulk modulus) decreased exponentially. The constitutive model for creeping considering the water degradation factor was planted into ANSYS. The numerical calculated results fit the experimental results of creeping test.

The failure tests on marbles under conventional triaxial loading were carried out. The ringing count rate of acoustic emission(AE) of rock，the frequency as well as the variation of b value at the failure stage and the sign of rock failure under various confining pressures were investigated. The experimental data were processed with the extreme-point symmetric mode decomposition method. The AE in the triaxial compression test was small at the compaction and elastic stages and was larger after entering the plastic stage and was increased significantly after the stress expansion. There was an AE quiet period before the peak strength. AE frequency and b value fluctuated all the time which varied drastically at the initial loading process and stayed at a higher level. At the plastic stage，they changed less and stayed at a lower level. Corresponding to the AE quiet period，there was a period that AE frequency and b value changed relatively small in the plastic stage. Under the lower confining pressures，the AE frequency before rock failure and the value of b dropped dramatically，indicating that the brittle failure of rock occurred. Under the higher confining pressures，the variations of AE frequency before the rock failure and the value of b was relatively stable，suggesting that the progressive failure in rock occurred.

A system for measuring seepage characteristics of the fractured rock with the water flow developed in-house is described in the paper. The normal and shear loads can be applied synchronously and asynchronously to the medium. The maximum loading is 1 000 kN and the maximum displacement is 100 mm. A new method of sealing was employed with the sealing ring set on the rock surface. The calculation of the permeability of the system was recommended according to the Darcy?s law and the Cubic law. Fine sands were stick onto the rock surface to simulate the roughness of the rock surface. The seepage tests were carried out using the system to the large size granite sample with a single fracture. The permeability was found to increase with the time until it reached a stable value. The seepage test was carried on the smooth(without fine sands) rock surface. The factor influencing the permeability was analyzed and the fine sands on the rock surface were found to be crucial. The testing results showed that the parameters obtained with the system were creditable.

To simulate the deformation behavior and the stability of rock mass under cyclic loading，the basic idea of subloading surface was presented. Considering the strength characteristics of rock under triaxial compression and under triaxial tension being different，i.e.，the lode angle effect，a corner model was introduced into the traditional Drucker-Prager yield criterion to form a modified Drucker-Prager yield criterion. Based on the yield criterion，a subloading surface model for the rock under cyclic loading based on the theory of subloading surface was proposed. Through the analysis of parameter sensitivity，it was found that three parameters including u，C and  of the model had a significant impact on Masing reaction and the ratchet effect of rock. To verify the applicability and validity of the model，a comparison between the simulation and the cyclic loading tests on the model material of rock and basalt was carried out. The results showed that the model described well the dynamic deformation characteristics of rock，indicating that the subloading surface model under cyclic loading was applicable to rock.

A model experiment with a scaling ratio of 1∶50 to simulate Qipanshi tunnel was carried out to investigate the deformation of overburden soil，the force and the damage feature of the tunnel under the effects of stick-slip dislocation of the thrust fault with the dip angle of 75°. The failure mode and mechanism of lining were analyzed. With the hanging wall rising，the fracture propagated to the surface and formed a triangular shear zone. The width of the shear zone was approximately 0.635D(D is the diameter of the tunnel) in depth at 2.5D，while 0.315D at the dome of the tunnel. Surface displacement was basically in accordance with the law of fault propagation. The longitudinal bending moment in the hanging wall zone was negative and positive in the foot wall zone. In the fault fracture zone，when the dislocation displacement was 0.34D，the cracks due to shearing and compressing occurred at the hinge joint. And some tensile cracks occurred in the local area. Serious damage only occurred at the hinge joint of the tunnel and the lining was slightly damaged. The effect of the anti-dislocation was much better than the tunnel without hinge joints.

In order to study the influence of the dip angle of bedding planes on the dynamic properties of bedding rocks，dynamic compressive and dynamic splitting tensile tests were carried out with 50 mm split Hopkinson pressure bars(SHPB) system on the bedding sandstone specimens with five different dip angles. The dynamic strain signals in incident bar and transmitted bar were monitored with the ultra-dynamic strain indicator. The process of dynamic crack development and the failure process of the sandstone specimens were recorded by a high speed camera. The effects of the dip angle(  or  )of bedding planes on the dynamic properties of bedding sandstones，including the relationships of the dynamic stresses and strains，the dynamic compressive and tensile strengths，the failure patterns and energy absorption properties were analyzed. The differences of interlayer were mainly the different contents of mineral compositions. It was found that the bedding sandstone specimens under the impact compressive loading generated five kinds of failure patterns with change of dip angles. With the increase of dip angle ，the dynamic compressive strength of bedding sandstone showed an inverted U-shaped tendency. Under the impact tensile loading，the splitting failure along the diametric loading direction occurred for all the Brazilian specimens. The dynamic tensile strength of bedding sandstone increased when the dip angle increased. The energy absorption ratio changed as the dip angle varied. With the proper loading angles(such as = 90° or = 0°)，the maximum energy absorption ratio was reached.

In order to investigate the tensile strength and failure characteristics of bedding coal rock under different loading rates，the static and dynamic Brazilian splitting tests were carried out with MTS815 rock mechanical test system and SHPB dynamic test system considering the vertical and parallel bedding directions. The results showed that the tensile strength of coal rock was anisotropic. The tensile strength of parallel bedding coal rock was greater than that of the vertical bedding coal rock. For the parallel bedding coal rock，the fluctuation of the tensile strength was greater with the increasing of loading rate and was significantly scattered. The vertical bedding coal rock had multiple fracturing modes. The strain rate had significant effect on the tensile strength and deformation. The tensile strength and strain rate were related linearly or in power function. The higher the loading rate was，the more severe the coal rock crushed. The composition and structural characteristics of coal rock were the important influence factors for the property discrepancy of coal rock and were the internal causes for the strength and deformation anisotropy of coal rock.

The long-term stability of gypsum pillars in Luneng Taishan Gypsum Mine was investigated with laboratory experiments，numerical analysis and in-situ monitoring. The results of uniaxial compression creep experiments showed that the strength of creep fracturing of gypsum was 72%–77% of the instantaneous strength and the previous modified Burgers model described better the creep properties of the gypsum. Based on the test results，the simulation on the long term stability was carried out to the gypsum pillar at 4301 workface. The deformations of roof and floor were found not in synchronous. The roof tended to be stable in about 3 years after mining，and the two sides tended to be stable in about 2 years after mining，but the floor tend to be stable as early as 1 year after mining. In about 10 years after mining，the deformations of roof-to-floor and the two sides are 155 and 68 mm respectively. The in-situ monitoring results demonstrated the creep of surrounding rock after mining. The deformation speed was bigger within 100 days after mining，and then it presented a fluctuated decreasing trend，but the deformation was still in slow growth. The stable time of roof-to-floor and two sides were different. The deformation of two sides tended to be stable within 400 days after mining and the deformation of roof-to-floor tend to be stable after 640 days.

The breakage of segmented lining has become one of the common problems of shield tunnels. The breakage mechanism of segmented lining in shield tunnels was discussed using the finite element method based on fracture mechanics from three levels，i.e.，a single segment，two segments with a joint and the whole lining ring. The bearing capacity and the failure mode of a single segment were found to be mainly affected by the boundary conditions. The failure of joints was in the form of opening at one side and crushing at the other side and eventually leading to the destruction of whole lining ring. The continuous joint model was found to be close to the real situation in modeling the mechanic behavior at a low load condition. The disconnection of two segments at the joint at a high load，and even the ultimate bearing capacity condition were not able be to be captured in the simulation，neither the concrete crushing around the joint. Therefore，the modeling of joint is the key in order to more accurately predict the bearing capacity and deformation of a whole lining ring.

The dynamic properties of quartz mica schist are complex and it is hard to determine the blasting parameter accurately. A lot of undesirable phenomena appear during the construction，i.e. the short advance per attack，overbreak and underbreak，which lead to the low efficiency. Through the indoor experiment of split Hopkinson pressure bar(SHPB)，the elastic modulus of quartz mica schist was found to change a little with the increase of strain rate in the linear elastic stage. In the nonlinear stage，the yielding characteristics similar to those of metal material occurred. The dynamic strength increased exponentially with the strain rate. Under the impact load，quartz mica schist was broken into the flake structure along the bedding direction，exhibiting the compressive-shearing failure mode. The broken degree was related with the strain rate. The breaking energy was linearly related to the incident energy. The breaking energy density increased with the increase of strain rate with a relation of a power function. The blasting process of a single hole with the diameters of aperture and explosive of 42 and 32 mm respectively was simulated. The time of forming blasting cavity and crack was about 0.904 8 ms. The radius of blasting cavity was 13.8 cm and 4.45 times the radius of the hole. The longest fracture was 71.3 cm in length and was 23 times the radius of the hole. The fracture zone was divided into 3 areas including a serious ruptured zone，a middle ruptured zone and a slightly fractured zone. The explosive pressure was reduced exponentially and was low in the distance of the 40 cm from the explosion center. The plastic zone was 49.3 cm in radius. The value of cuthole blasting parameters of an underground cavern of actual mica quartz schist was proposed.

A single rotary rock block model with the revised step voussoir beam was proposed and a formula calculating the working resistance was established. For the roof structure of the shallow fully-mechanized face，i.e.，31201 working face of Shigetai coal mine in Shendong mining area，three different conditions according to the overlying coal seam which was the solid coal，or the room and pillar goaf or the concentrated pillar in room and pillar goaf were considered so that the roof structures were proposed as a voussoir beam-single rotary rock block，a slight dislocation voussoir beam-single rotary rock block and a severe dislocation voussoir beam-single rotary rock block respectively. The mechanical model of the single rotary rock block was used to calculate the working resistance of support under different roof conditions in Shigetai coal mine. The results showed that the working resistances calculated with the model in different roof structures were correct and the crushing accident of the support cannot be avoided by increasing the working resistance only.

In order to study the dynamic characteristics of high frequency vibratory driving in sand foundations，liquefaction experiments with different vibration frequencies on saturated dense sands were conducted by using the high-frequency cyclic triaxial instrument. The mathematical equations describing the relationship among time (t)，number(NL) and frequency(f ) were derived according to the experimental results. The influence of the frequency on dynamic pore water pressure changed with the time and the number of vibrating cycles was studied. The relationship between the ratio of pore water pressure and the ratio of cycles was obtained in this study and was compared with the model proposed by Seed. The shapes of the curves were found to be affected by the frequency. The vibration frequency had the significant influence on the development of axial strain in the dense sands during the high-frequency cyclic triaxial tests. Before the sands achieved liquefaction，the axial strain was slightly changed with the variation of the frequency under the same number of cycles and at the same time. The change of the frequency had great effect on the relationship between the ratio of axial strain and the ratio of cycles.

The seismic subsidence of loess is greatly affected by the changes of water content and the corresponding influence is valuable for the evaluation and predication of the seismic subsidence of loess site. A series of dynamic triaxial tests of undisturbed loess under different water contents were carried out. The influence of water content on the seismic subsidence of loess was analysed and the evaluation and predication of the seismic subsidence of the sampled loess site were presented. The results showed that the coefficient of loess seismic subsidence increased with the increasing of the dynamic stresses or water contents. The critical dynamic stress of seismic subsidence decreased with the increasing of water contents. The seismic subsidence of loess with different physical properties was significantly different. For the loess site with water content no more than 5%，the seismic subsidence would generally not occur under the earthquake intensities of VII or VIII，while for that with the water content larger than 5%，the seismic subsidence would occur under earthquake intensity of VIII.