After brief introduction of geological processes responsible for rock global circulation，the topic of geological nature of rock is put forward and discussed with emphasizing the intrinsic properties of rock substance，structure and occurrence state，as well as its close relationship with geological evolution. The difference between rock and other artificial material lies in the geological nature of rock formed in the geological evolution. Based on the recognition of rock nature，the origin of physical inherent properties is discussed including heterogeneity and discontinuity，and their relations with geological nature are also discussed. Brief discussion on constitutive property in rock mechanics is made. The paper attempts to establish a knowledge path from geology to rock mechanics for further collaboration.

For the excavation damage zone(EDZ) in underground construction，seepage is greatly influenced by the stress in the surrounding rock and the water pressure in cracks. For example，seepage velocity will increase with the water head pressure gradient increasing，and then the seepage becomes nonlinear instead of Darcy flow. So the properties of nonlinear seepage in cracked marble under different hydrostatic pressures and water pressures are focused on. Firstly，the seepage tests are performed using the self-developed temperature-stress-hydraulic coupling test system. According to the test results，the evolutionary law of seepage under different water head pressure gradients can be divided into three stages，namely，steady Darcy seepage，transition from Darcy seepage to nonlinear seepage and nonlinear seepage；and a complete quadratic polynomial is proposed to describe the relationship between water head pressure gradient and seepage velocity. Secondly，the relationship between critical water head pressure gradient and lateral deformation of rock specimen is described by a linear equation based on the deformation data；and then an empirical function is proposed for crack hydraulic aperture and the lateral deformation of specimen. Finally，the evolution of crack hydraulic aperture is studied，which is responsible for the variations of the critical water head pressure gradient，inherent permeability and quadratic term coefficient. Two conclusions are drawn as follows：(1) with the hydrostatic pressure increases，the crack hydraulic aperture reduces，which leads to reduction of the inherent permeability while augments of the critical water head pressure gradient and the quadratic term coefficient；and (2) with the water pressure increases，the crack hydraulic aperture increases，accordingly，the inherent permeability increases，but the critical water head pressure gradient and the quadratic term coefficient reduce.

Triaxial rheological tests are carried out on marble samples from Jinping Hydropower Station on TLW–2000 creep testing machine. The stress-strain-time curves of the marble samples are obtained under the condition of step unloading confining pressure and constant axial pressure. According to the rheological deformation properties of marble samples under unloading condition，a 3D elasto-viscoplastic constitutive model based on Cristescu consititutive model is developed considering the effect of lateral unloading；and the parameters of the model are obtained. The model overcomes the defects of 3D component models which can not consider the effect of stress path and hardly show the lateral rheological deformation law. Comparison between the results obtained from the improved model and tests shows that the proposed rheological model can describe the overall rheological deformation law of rock with time under unloading stress path.

The seismic safety of a high arch dam is studied through shaking table test and numerical simulation. The dynamic characteristics of the high arch dam system，weak portions，failure mode，as well as aseismic behaviors during earthquakes are discussed. A type of brittle material which has the same characteristic as the common concrete is used to study the dynamic failure process of high arch dam adopting the step loading method on shaking table. The dynamic characteristics，the change law of dam acceleration and dynamic strain are investigated. An elasto-brittle damage constitutive model is applied to simulate and analyze the dynamic failure process of high arch dam under meizoseismic motion. The comparison between the calculated results and those obtained from shaking table tests shows that they are close and definitely verified each other. The study also shows that the top of arch crown and one-quarter point of both sides are the vulnerable parts of arch dam and cracks normally appear near these parts under meizoseismic motion along stream direction. The cracks along the stream direction cut across arch dam and concrete block falls down from the top of arch crown. The arch dam is endangered to the impounding function and the structure bearing capacity. Vulnerable parts of the dam to earthquake loading and various factors that affect the earthquake-resistant behavior of the dam，such as the openings existing in the dam body，are discussed under meizoseismic motions of different levels. These researches provide basic data for performance-based aseismic design of high concrete arch dam.

Based on the static tests of five compressive piles of Lucheng Square in Wenzhou City，some conclusions of post-grouting compressive pile under different loads are drawn. Although grouting pressure changes at any time，it has a dynamic variable range. Post-grouting technique can solidify bottom sediment and mud cake around pile，and improve the bearing capacity of pile. Axial force of compressive pile decreases with the increase of soil depth，and that of pile bottom gradually increases with increasing load. Compressive deformation of pile is the major part of settlement of single pile for scree stratum after grouting，which accounts for over 80%. The developing degree of side resistance is well corresponding to the relative displacement between pile and soil. When the relative displacement between pile and soil increases to a certain value，the side resistance will decrease with the increase of load，i.e. side resistance softening phenomenon happens. Though very little relative displacement between pile and soil occurs，the side resistance of soil close to pile bottom will increase sharply.

Based on improved Newmark¢s implicit integration method，the earthquake-induced dynamic responses of Galongla Tunnel along Zhamo Highway in Tibet are studied using infinite element dynamic artificial boundary technique；and aseismic mechanism of seismic isolation layer is analysed. Furthermore，the shock absorption effects of two kinds of seismic isolation layers，which are made of rubber and foam concrete respectively，are studied and compared those with numerical method. The results show that better shock absorption effects can be achieved because of the good isolation and cushioning effects of the seismic isolation layer despite that the dynamic response of the tunnel cannot be changed essentially. It also can be seen that there are small differences in shock absorption effects between two kinds of seismic isolation materials；however，foam concrete is recommended because of its durability and economy. Results of this research can provide certain references to stability analysis of underground engineering in highly seismic regions.

Stochastic granule discontinuous deformation(SGDD) model is presented from mesomechanical view；random distribution model of rockfill granule is built by Monte Carlo method；and nonlinear contact algorithm is presented based on modified augmented Lagrangian algorithm. SGDD model may simulate effectively interaction of rockfill granule and tip rupture. Triaxial samples of rockfill are simulated by SGDD model；and the movement and deformation processes of rockfill granule also re-emerge. The numerical calculation results show that SGDD model can simulate the instantaneous deformation process. Scale effect of laboratory test for rockfill is also discussed. Two groups of rockfill samples，a reduced scale gradation and another real one，are simulated by SGDD model. It reveals that the real scale gradation shows less deformation and higher initial modulus of elasticity under the same axial stress and confining pressure without considering creep and humidification deformations of rockfill.

The main issue considered both in design and construction in urban environments is constrolling ground movement to keep the safety of existing buildings. Based on a shield tunnel construction in Shanghai，the ground displacement distribution around tunnel is studied by field measurement and numerical analysis. It is shown that the influence of shield excavation on soils around tunnel can be divided into three stages，including shield approaching，crossing and leaving the measuring holes. While the shield approaches and crosses the measuring holes，the ground movements of lateral soil behave heaving，moving along the shield tunneling direction and outward the tunnel. Settlement，moving along the shield tunneling direction and inside the tunnel are main deformation characteristics when the shield leaves the measuring holes. Settlement and forward movement the soils above tunnel because of the large buried depth. According to the calculated layered settlement above tunnel，modified Peck formula used to predict the settlement of deep soils is established；and the results are compared with those of simulation.

Integrity of rockmass has two parts of meanings，i.e. rockmass cutoff degree and rockmass fragmentation degree. Discontinuity length and spacing should be considered both in describing rockmass integrity，rather than the latter only. Rockmass cutoff degree and rockmass fragmentation degree are studied using spatial block identification technique. The results show that the greater the ratio of trace length to spacing of discontinuity is，the higher the cutoff degree is and the lower the integrity is. When the ratio of trace length to spacing is 3–4，the rockmass is divided into relatively discrete rockmass，which corresponds to comparative cracked one，i.e. the transition stage of complete to fractured rockmass，accordingly the rockmass structure type is inferior blocky. The rockmass fragmentation degree is not only dependent on discontinuity spacing，but also relevant to the ratio of trace length to spacing. When the rockmass is cut as block entirely，the fragmentation degree is controlled by spacing mainly. These conclusions can be used as supplementary conditions in classification of rockmass integrity and rockmass structure type. Furthermore，based on the conclusions drawn above，the influence of different distribution types of trace lengths with lognormal distribution is discussed. At last，the rockmass integrity and structure type of typical engineering are analyzed according to discontinuity statistic data. The research ways and the conclusions are of importance to further study of rockmass integrity.

Platform has a good function to baffle dangerous rock masses movement after falling. Based on stopping and accumulation effects of experiments of platform on rolling rock blocks，the stopping position and the average resistance coefficient of rock blocks on platform are analyzed by using the multivariate nonlinear regression model. The relations between the stopping position and the major factors such as the rock block mass，the rock block shape，the velocity of the rock block just falling on the platform，and the roughness of the platform surface，are analyzed. And the relations between the average resistance coefficient and these factors are also analyzed. Then the factors relativity is analyzed. Moreover，the multivariate nonlinear regression model is predicted. Finally，the effect of rock block mass on the stopping position is analyzed specially. The following results can be drawn. (1) The stopping position and the average resistance coefficient are influenced by rolling rock block mass，shape，velocity when just arriving at platform，and the roughness of the platform surface. Their relations can be expressed by the multivariate nonlinear regression formulas. And the predicted stopping position and average resistance coefficient by the method nearly coincide with practical ones. (2) The mass of rolling rock block，initial position(slope height)，and the roughness of the platform have a certain influence on the stopping position. In other words，the stopping position of the rolling rock block and its mass accord nearly with power function. The more the rolling rock block mass is，the higher the slope height is，and the longer the displacement on the platform is for same mass of rolling rock block. Then new feasible methods to prevent potential unstable rock masses are put forward. The results are helpful to make out a draft for geohazards prevention.

Jet grouting(JG) soil-cement-pile strengthened pile(JPP) is a new kind of composite pile composed of high-pressure jet grouting pile and prestressed core pile. In order to make a further research on load transfer mechanism of single JPP with cap，the large-scale model test has been done on the self-developed foundation model slot. With the prearranged instrument in JPP and soil under cap，the following main characteristics of load transfer are drawn. (1) Compared with single JPP，JPP with cap has larger bearing capacity，and the ratio of load carried by cap is higher. (2) The relative displacement between JPP and soil is controlled by cap，which leads to the fact that the friction resistance does not exert sufficiently. (3) Pile-soil stress ratio of JPP with cap is between 20 and 100，and the ratio on the pile top is around 22，about twice the ratio of cap area and pile area. (4) The cap of JPP makes friction resistance decrease and tip resistance increase；and the displacement of the ultimate resistance is larger than that of JPP without cap. These results are beneficial for cap-JPP-soil interaction research.

wall cracks appear on the house No.6 near the deep pit foundation of open-cut tunnel. With the characteristics of the cracks and construction design，safety monitoring in the area is conducted，which include house cracks，house settlement，displacements of deep soil，horizontal displacements of piles，blasting vibration，etc.. According to the numerical simulation and the monitoring results with rapid cracking in three stages，the causes of cracking are analysed，which exclude the factors such as uneven settlement，temperature difference，slope instability，anchor tension，etc.. The results show that dynamic load is the main factor which causes the rapid expansion cracks；and the mechanical properties of the wall are weakened by punch pile construction as well as cracks induced by blasting，and the original cracks will expand continuously if the vibration velocity of the wall is greater than 1.0 cm/s in several days. It is also shown that the temperature difference of environment has effect on expansion width of crack. Based on the above results，strict control measures for vibration velocity are adopted in blasting operation near the house No.7，making the original crack in house No.7 expand much slower than those in the house No.6 before being deal with，so that the cracks in the house No.7 are well controlled during the construction period，and the safety of the house is ensured.

It is aimed to propose a systematic quantitative method for system reliability analysis of rock slope with plane failure considering multiple correlated failure modes. A probabilistic fault tree approach is presented to model system reliability of rock slope considering multiple correlated failure modes. The versatile 4-parameter b distribution is used instead of a normal distribution or a lognormal distribution，which is adopted for describing the location of tension crack，the cohesion along the failure surface and the friction angle. The truncated exponential distribution is used for the percentage of tension crack filled with water. The adaptive importance sampling(AIS) method is employed to perform the system reliability analysis of rock slope with plane failure. System reliability sensitivity with respect to distribution parameters of random variables is performed. Results from a numerical example indicate that the system reliability of rock slope considering multiple correlated failure modes can be effectively evaluated using the probabilistic fault tree approach，which will be underestimated without considering the correlation between failure modes. The failure mode of block A failing without interaction force due to block B has the higher probability of failure than that for the failure mode of block A with interaction force due to block B. Both the mean sensitivity coefficient and the standard deviation sensitivity coefficient indicate that the percentage of tension crack filled with water and the location of tension crack are significant random variables with higher sensitivity coefficients. Therefore，to improve the slope stability effectively，a good drainage system of the slope should be designed and a detailed geological investigation of discontinuities in the rock mass should be conducted. The mean sensitivity coefficient and the standard deviation sensitivity coefficient are strongly related and both can be used to identify key contributing random variables.

The landslide with double sliding plane and rock-layer reverse exists in the nature universally. Taking Hanjiaya Landslide along Xiangfan—Shiyan Expressway for example，which has the representative characteristics of the landslide with double sliding plane and rock-layer reverse，many research methods such as in-situ investigation，physical simulation，in-situ monitoring，numerical simulation，etc.，are comprehensively adopted to analyze the basic characteristics，formation and development conditions，deformation and failure mechanisms of this kind of landslide. In order to expose the basic characteristics，form and development conditions of the landslide with double sliding plane and rock-layer reverse，various engineering geological methods are adopted，such as geological drilling，costeaning，trenching，geophysical survey，surface investigation，etc.. The positions and the basic characteristics of two slip surfaces and the front rock-layer reverse characters are ascertained by in-situ monitoring. Large-scale geomechanical model test and the technology of digital close-range photogrammetry are adopted to measure displacement field. The physical emulation is used to study the development，evolvement and formation processes in long geological history in laboratory and the gradual failure process of curvature and rupture on reverse rock-layer. Finite element method is adopted to calculate and analyze the deformation and failure mechanisms and the rock-layer reverse cause. The numerical simulation results and the practical ones，the in-situ monitoring and the physical simulation results coincide with each other. The research provides a scientific basis for mechanism study and treatment of the similar landslides.

Based on the rock mechanical experiment on low porosity and low permeability sandstone under different confining pressures and synchronous collecting experiments of transit time intervals of longitudinal and transverse waves and wave patterns of those rocks，the behaviors of acoustic velocity，amplitude and frequency spectrum properties under triaxial and uniaxial loadings are studied. The following conclusions can be drawn. (1) The velocity and frequency spectrum properties of longitudinal and transverse waves change with rock deformation and failure stages. In the stage of fracture and pore compaction inside rock，the velocities of the longitudinal and transverse waves increase rapidly. The ratio of axial stress corresponding to peak velocity of longitudinal and transverse waves to compressive strength of rock decreases as the arithmetic product of porosity and permeability increases. (2) The changes of longitudinal and transverse waves patterns are closely related to rock deformation. As the axial load increases，the fractures in rock generate and develop；when the axial stress reaches 60% of the limit strength，obvious scattered wave signal appears at the end of the transverse wave pattern. (3) As the axial load increases，rock is compacted，and the amplitude of frequency spectrum curve increases as well. When the axial load increases further，the fractures will appear in rock；and low frequency signal is more active than the high frequency one in frequency spectrum curve. (4) In the stage before rock strength reaches peak value，both the first arrival wave amplitude and the principal amplitude tend to increase. In the stage of elastic compression，the two kinds of amplitudes increase rapidly，while in the stage of unsteady fracture expansion，the principal amplitude tends to increase more slowly than the first arrival wave amplitude. It is of theoretical and practical significance to predict rock fracture and its long-term stability.

The earthquake is one of main factors resulting in failure of underground caverns. The dynamic response analysis of rock caverns under seismic load is a hot issue during the construction of hydraulic engineering in highly seismic region in West China. The dynamic time-history response analysis method is used to analyze the dynamic stability of Liangjiaren Hydropower Station on the Jinsha River. The trends of relative displacement and point safety factor of underground caverns are studied under the natural seismic wave；and the changing law of displacement when the seismic wave passes through caverns is analyzed；also the aseismic effect of lining is discussed. The results show that seismic wave propagation is affected by medium，structural plane distribution and cavern free surface；the fluctuating laws of the maximum relative displacement and point safety factor are similar with those of seismic spectra and the vibration is enlarged around the rock caverns；also bigger permanent displacement has not been discovered in underground cavern walls and fault F4. After the lining has been applied，the vibration intensity is reduced，the stiffness of the surrounding rock is increased and the surrounding rock bears a larger seismic load，producing a smaller displacement when the lining has bigger rigidity；also the maximum relative displacement and the permanent displacement decrease by 10.88% and 29.20% respectively. The practice shows that the aseismic effect of underground caverns with lining is good. The presented research can provide some references to similar projects.

Possible effects of changes in soil shear strength induced by acid rain on landslide formation are investigated. Soil samples from freshly exposed slip surface and adjacent surface have been studied at two landslides in the Three Gorges Reservoir area，China. A visibly higher smectite content at the slip surface and a dominant content of illite in the adjacent surface are observed. In laboratory，remolded soils are subjected to acid water immersion and tested for changes in their mineral compositions and shear strength after immersion with different durations. The largest change occurs in the internal friction angle，which drops over one-third，going with the change of the original smectitic soil with a substantial illite component into completely smectite dominated soil. Subsequently the internal friction angle rises back，simultaneously with neoformation of kaolinite at the expense of the smectite component. Changes in cohesion are much less significant. The original koalinite-rich and illite-rich samples are found to be much more stable. A chemo-mechanical model of clay is discussed at last.

Due to the large-scale vertical loads，a relative movement can be induced when the soil settles in relation to the pile. Thus，the negative skin friction occurs if the movement of pile is upward.Taking the in-situ test of negative skin friction on punched cast-in-place pile of Ninghai Power Plant Project for example，the influence of the soil consolidation around pile on the downdrag forces and the position of neutral point are studied. Different subsurface soil settlements are measured within and outside the two sets of piles，suggesting different influential degrees of the piles on the surrounding soil. The positions of the neutral point obtained from the measured settlement curves of soils and piles agree with the ones from the variable curve of pile axial force with depth. The measured maximum coefficients of side skin friction around piles are consistent and they vary between 0.3 and 0.4. Furthermore，based on the test results，the effect of pile construction technology on negative skin friction is analyzed. It is commended that the calculation of the settlement distribution is emphasized in the design for the negative skin friction piles. These conclusions are useful for engineering practice，which may guide the design and construction of similar projects.

With the resources exhaustion of medium-sized thickness and thick coal seam，more than 10 mines will be transferred to the lower coal group in Lu¢an Group. The occurrence mode of coal seams #15–1 and #15–3 in the lower coal group is thin coal seam group with average distance 4.4 m. Therefore，the conventional staggered distance model of ultra-close thin coal seam group during combined mining is put forward；and the theoretical research and physical simulation are carried out. The conventional staggered distance formula is proposed. To avoid interaction between the roof periodic caving of coal seam #15–1 and the leading effect of coal seam #15–3 in mining，from the point of safety，the conventional staggered distance is confirmed as 1.3–1.5 times of the roof periodic caving span of coal seam #15–1. Combined with the experimental results，the conventional staggered distance is determined as 17.5 m. Physical simulation test results show the feasibility of the conventional staggered distance in combined mining. In addition，the elevation reason of several measuring points on the top of the working face near coal seam #15–1 is analyzed；and the roof subsidence phenomenon，which has mainly two major changes during the course of working face advance，namely，the roof caving in the stoping course of upper and lower working faces，is summarized，especially the roof caving of lower coal seam which will have larger influence.

Experiments are carried out to study coarse sandstone on upper plane of coal bed of Fangzhuang Coal Mine of Jiaozuo Co.，Ltd. under conventional triaxial compression by the MTS815.03 servo-controlled testing machine after high temperature. Based on the experimental results，the macro-mechanical properties of coarse sandstone under conventional triaxial compression after different temperatures are investigated. The relationships between triaxial compression strength，average modulus，cohesion，internal friction angle and peak strain of coarse sandstone and temperature are analyzed；and those between strength，average modulus and temperature are also studied. The results show that，when the confining pressure imposed on coarse sandstone is constant，and the temperature changes from 25 ℃ to 300 ℃，with the increasing of the temperature，the triaxial compression strength，average modulus，cohesion，internal friction angle all gradually increase，but the peak strain has a slightly decrease. The thermal stress generated by high temperature has an effect of absorbing deformation and closure of fracture，parts of the original fracture get close；the number of fractures decreases；the compaction rate uprates；the contact relationship of mineral grain has been improved；and the frictional characteristic has been enhanced. When the temperature is over 300 ℃，with the increase of temperature，the triaxial compression strength，average modulus，cohesion，internal friction angle all decrease；but the peak strain has a little increase. And the discordant thermal expansion which happens across mineral particles can induce structural thermal stress due to the different thermal expansion coefficients of mineral particles in coarse sandstone. Then the microcracks develop inside the sample which makes the bearing capacity and non-deformability decrease. And the confining pressure can improve the mechanical properties of coarse sandstone. When the temperature is internal，with the increase of confining pressure，the strength，average modulus，cohesion，internal friction angle of coarse sandstone gradually increase.

Double-yield surface models for soils are firstly reviewed；and the necessity and reasonability of the concept of double-yield surface are confirmed. Based on a series of tests carried out by an improved plane strain test apparatus on Toyoura and Seto sands，a new double-yield surface model is proposed. The functions for elastic property，plastic volumetric property and plastic shear property in this model are derived directly from the test results with less hypothesis. Young¢s modulus and Poission¢s ratio are derived separately as functions of mean principal stress sm. The spherical surface is adopted as volumetric yield loci and the plastic work is used as hardening parameter. For shear yield loci，a function of principal stresses is adopted，which is derived from the test results and similar to that of Matsuoka model，but the hardening parameter is revised to couple with the unique relationship between hardening surface and the parameter. To simulate the hardening-softening process of the yield loci，the hardening function is built by combining a hyperbolic function and an exponential function. Nonassociated flow rule is adopted for plastic shear property based on test results. To make it convenient to be applied to numerical analysis，the elastoplastic rigid matrix of the model is derived. Finally，by using the parameters derived from the test results，verification of the model is carried out by both interpreting laboratory test results and applying it to calculation of the deformation of a high soil-fill project，Both cases agree well with each other，indicating a potential application of this model.

Four shrubs planted in PVC pipes in the testing areas are studied；then direct shear tests on the undisturbed soil and root-soil composite system are conducted. By comparing the shear strength indexes of the soil without root and four kinds of soils with roots，the mechanical effects of the root system of four shrubs with one-year growth period on slope protection can be evaluated. Comparison between the shear strengths of four- shrub root-soil composite systems is made to evaluate the enhancement effect of the systems for slope protection. The results show that：(1) when the root and water contents of the four-shrub root-soil composite systems keep constant，the shear strength increases linearly with increasing vertical pressure，indicating that the direct shear strength of the root-soil composite systems agrees with Coulomb law；(2) the cohesion of the root-soil composite systems is obviously larger than that of soil without roots，and there are no apparent changes in the internal friction angle；(3) compared with the cohesion of soil without roots，the increasing amplitudes of the cohesion of Atriplex canescens，Caragana korshinskii，Zygophyllum xanthoxylon，Nitraria tangutorum are 76.3%，62.7%，45.8% and 22.0% respectively. The relations between the shear strength and displacement of the root-soil composite systems show a linear relationship at the beginning stage of the shear process，a rounding curved relationship at the end of the shear process，and an approximate horizontal relationship when shear failure. The shear stress of the root-soil composite systems increases obviously with increasing vertical pressure，in which the increasing rule of shearing strength agrees with linear relationship at the beginning of the shearing process，basically linear at the beginning and nonlinear when approaching failure. According to the strengths of the four-shrub root-soil composite systems，the mechanical effects of the four one-year growth period shrubs for slope protection are as follows：Atriplex canescens＞Caragana korshinskii＞Zygophyllum xanthoxylon＞Nitraria tangutorum.

Taking Dahuofang Water Transfer Project in Liaoning Province as background，the monitoring technique of tunnel clearance displacements in the tunnel boring machine(TBM) bid segments is introduced under condition of TBM construction. Based on the tests，a monitoring method of TBM tunnel clearance displacements with laser collimation is proposed. It comes true by utilizing the longitudinal intervisible space between the boring machine and tunnel profile and using the laser collimation method to the three measuring points on the crown and two sidewalls. Thereby，the problem that the tunnel clearance displacement under condition of TBM construction is difficult to be obtained with existing monitoring methods can be resolved. Also，the SWL–I tunnel laser displacement monitoring system with satisfying measuring precision，simple and easy-to-operate characteristics is developed. The system has been applied and verified in the construction of Dahuofang Water Transfer Project by use of Robbins and Wirth¢s open TBMs. The displacement characteristic curves of surrounding rock in the tunnel crown and both sidewalls at the end of the machine cutterhead are obtained firstly；and the monitoring of tunnel clearance displacements under condition of TBM construction has been realized.

Bedding slope is the most unstable and most easily deform and fail for all kinds of rock slopes. The upper limit of intersection angle between trend of slope and strata is closely related to rock hardness of bedding slope. In order to analyze the influence of intersection angle between trend of slope and strata on the stability of bedding slope，stability calculating model of bedding landslide is built. Considering the lateral resistance of bedding landslide，according to rock bridge transfixion theory of shear test，the T2b2 and T2b3 rocks are selected as the representatives of soft and hard rocks respectively to analyze the sensitive degree of influence of different intersection angles between trend of slope and strata of bedding slope on slope stability. Finally，the upper limit of angle between the trend of slope and strata for bedding landslide is determined. It is indicated that the slope stability of hard rock is more sensitive than that of soft rock when the intersection angle between the trend of slope and strata changes. It is reasonable that upper limit of the angle for a bedding landslide is 30°. The conclusion is verified by landslides between head of reservoir to Badong in the Three Gorgers Reservoir. The analytical results are very important to analyze the stability of bedding slope and to divide slope structures in potential landslide mapping.

It is very difficult to resolve or measure matric suction in engineering practice，because the matric suction is not constant especially under undrained condition. The degree of saturation is relatively easy to be measured，so the shear strength formula about saturation degree instead of suction has valuable significance in practical engineering. A new formula based on strength indexes of saturated soil is proposed，which can be used in whole engineering practice range including unsaturated soil and saturated soil. More intrinsical characteristics of engineering can be reflected. Proper parameters for Yunnan red clay in the above-mentioned formula are determined based on the results of soil-water characteristics and constant water content triaxial tests. Finally，the undrained shear strength formula is utilized to analyze the bearing capacity of foundation；and the conclusion that the bearing capacity increases with the reduction of degree of saturation linearly is drawn.

Damping level of a system is vital in dynamic response analysis. In civil engineering，damping ratio is commonly employed in characterizing the damping level of structure and is of great importance in aseismic design. But so far，for most conventional building aseismic designs，the influence of the soil-foundation interaction on the structures is disregarded. The damping ratio adopted in current aseismic design is based on the experiments carried out on rigid soil-foundation. Since the soil-structure interaction(SSI) effect is universal，for the dynamic responses analysis of an in-situ building，it is in accordance with the actual case to involve SSI effect. For aseismic design of structures involving SSI effect，accurate experimental evaluation of damping ratios of SSI system is a necessary prerequisite. To accurately get damping ratio of the system，many identification methods have been proposed and developed. But so far，most of them cannot achieve success in identifying accurate in-situ damping ratios of buildings，i.e. SSI systems mainly because of the fact that the responses are significantly influenced by noise. In order to accurately evaluate the damping ratio of building involving SSI effect，a combined identification method using ambient excitation technique is proposed and simply introduced. Based on this method，the damping ratios of 82 in-situ buildings located in Xi¢an and their vicinal regions，which include all kind of upper structures in various materials，are investigated. The numerical range of damping ratios of the actual buildings involving SSI effect is shown as well as their distribution pattern. By means of a fitting curve，the variation tendency of damping ratios of in-situ buildings is revealed. And then，the influence factor of the damping ratios of actual buildings is preliminarily analyzed.