Based on the uniaxial compression test，the mechanical properties of tuff，granite and breccia after different high temperatures are studied. The scope of this research includes(1) the variation of peak stress，peak strain and elastic modulus with temperature，and (2) the relationship between longitudinal wave velocity and peak stress and peak strain. The temperature varies in the range of 20 ℃，200 ℃，400 ℃，600 ℃，800 ℃，and the heating velocity is 30 ℃/min. The results show that the peak stress and elastic modulus decrease with temperature. The higher the temperature is，the larger the decrement of the peak stress and elastic modulus are. For tuff and granite，the peak strain increases with temperature. However，for breccia，it seems that the peak strain decreases with temperature. Furthermore，the relationship among longitudinal wave velocity，peak stress and peak strain present different laws according to the types of rocks.

This paper presents a three-dimensional numerical modeling method associated with actual mesostructures for heterogeneous geomaterials. Firstly，digital image techniques are used to extract two- dimensional material heterogeneity from material surface images. Secondly，the 2D square mesostructures are extrapolated to form 3D cuboidal mesostructures with the assumption that the material surface is a representation of the inner material distribution within a very small depth. Thirdly，an iterative milling and scanning system is set up to remove the material surface layer at a very small depth. The newly exposed surface is scanned to form the new digital representation of material heterogeneity. The milling and scanning process is repeated until the entire specimen can be represented by a series of layers of the cuboidal elements. These one-layer-thick 3D mesostructures are connected in series to form the actual 3D mesostructures. Finally，the 3D mesostructures are incorporated into traditional numerical methods to examine the mechanical behavior and fracture patterns of heterogeneous geomaterials under external loadings. A Hong Kong granite specimen is used to demonstrate the procedure of the 3D mesostructure establishment. The granite heterogeneity consists of three minerals：biotite，quartz and feldspar. A 40×118×10 cuboidal model is established. The actual size of the model is 15.00 mm×44.25 mm×3.56 mm. By adopting the commercial finite difference code FLAC3D，the 3D stress distribution，crack propagation process and failure model of rock under uniaxial compression loadings are simulated. Three homogenous cases and one heterogonous case are studied. The stress distribution and failure patterns associated with the three homogenous cases and a heterogeneous case are different. The load and displacement curves show that the compressive strength of the heterogeneous case is lower than those of the homogenous cases. The numerical results indicate that material heterogeneity can play an important role in the failure behavior as well as fracture patterns of geomaterials under external loading.

It is well known that rock properties often vary from site to site，and even from specimen to specimen. So，in many cases，it requires many rock samples，much effort and cost to obtain the reliable data. In order to make more rock samples to carry out rock mechanical strength tests in the laboratory，a testing method with a small rock specimen (10 mm in diameter and 20 mm in length) was proposed and developed. In the triaxial compression test，the transparent triaxial vessel made of an acrylic acid resin，developed by Okubo et al.，was modified and used for the small specimen. The transparent vessel was designed for triaxial compression test under confining pressure up to 10 MPa. It was found that the mechanical parameters，cohesion and angle of internal friction，of Tage tuff with small specimens are very similar to the results obtained from regular specimen. Furthermore，the loading rate dependency of a stress-strain curve was also obtained by just one small specimen with the loading rate alternately switching during a test. The rock collected from landslide area near the Three Gorges Reservoir was also examined. By the proposed method，the strength characteristic curve and the loading rate dependency of the sample rock were accurately and economically obtained.

When the displacement finite element model is applied to numerical calculation in geotechnical engineering，ill-condition problems often occur. This paper comments on these problems such as extreme anisotropy，incompressible or nearly incompressible material as well as shear locking in plate，etc. and researches the characteristics and applicable situation of many methods to conquer ill-condition problems such as regularization，standardization and splitting elastic modules finite elements. By the example of calculating plane bar-system problems with finite element method，the advantages and disadvantages of regularization，standardization and splitting elastic modulus finite element method are analyzed and compared.

Digitalization of underground engineering is part of the development strategy of digital earth，and it is also one of the main new developing fields in the research of underground engineering. This paper first examines the concept and research of the terms such as 3D GIS，digital stratum，3D strata visualization，and virtual reality of underground engineering. Then the concept of digitalization of underground engineering is clearly defined，that is，based on digital stratum and the technology of informatization，digitalization of underground engineering provides an integrated and effective way for the data management of underground investigation，design，construction，monitoring etc. in the construction process，and an information sharing and analytical platform for the building，management，running，maintenance and disaster prevention of underground engineering. The objective of digitalization of underground engineering is to build a digital museum of underground engineering for all life cycle. According to the concept，a system architecture of digitalization of underground engineering is then put forward. The system architecture is comprised of five levels，which are data layer，modeling layer，representation layer，analysis layer and application layer，and functionality of each layer is also described. It is also proposed that the software development of each layer should be implemented by component technology. Finally，some preliminary application examples of digitalization of underground engineering are put forward，and some research trends in the future are discussed，too.

Changes in permeability due to stress variation in fractured porous rock media have important impacts on engineering design. Therefore，it is of vital importance to couple stress and fluid flow effects when dealing with practical engineering problems. For example，when mining near an aquifer，the mining-induced stress redistributions cause changes in the inherent permeability，which may result in water intrusion into the mining workings. In this paper a modified cubic law is adopted for a fractured media，and stress-aperture-permeability relationships are derived in a three-dimensional domain by using stresses and matrix-fracture interactive model. In the porous portion，permeability is to a great extent controlled by the pore geometry，which is a function of the applied stress. A model has been developed to determine the three-dimensional stress-permeability relationship, assuming that the solid grains in the porous medium are the cubical grain packing structure. Surface subsidence induced by mining and drainage in porous aquifers is also studied using poroelasticity. A finite element model incorporated with coupled stress and flow in fractured porous media is developed. The model is then applied to examine permeability changes，strata failure，and surface subsidence in a coal mine for different mining geometries. The results show that the permeability around the mining panel increases as the length of mining increases. Also surface subsidence depends not only upon the thickness of mining，but also upon the pore pressure withdrawal. The simulated results are in good agreement with the observed data.

Geosynthetics-reinforced earth retaining walls have been widely employed in geotechnical reinforcement engineering practice. As one of the key issues in design and construction of the reinforced earth structures，more attentions have been paid to the rational evaluation of long-term performance of reinforced earth structures. A numerical procedure based on finite element method is presented for analysis of behavior of deformations and stresses of reinforced earth structures. The nonlinear creep behaviors of both filling soils and geosynthetics used for reinforcement are taken into account by using the rheological models of viscoelasto- plasticity and nonlinear viscoelasticity respectively. Additionally，the interaction effects of reinforcement and fills，panel and fill as well as panel and panel are rationally considered by using Goodman¢s joint element model. The layer-by-layer filling process of backfills of retaining wall is also simulated. Nonlinear computations based on 2D FEM are numerically implemented by hybrid algorithm in which the incremental scheme is incorporated with iterations by using the initial-strain procedure. Based on the test results of Denver test wall of clay soil，the computational parameters are evaluated. The proposed method is applied to analyze of Denver test wall. The reliability and reasonability of the proposed method are verified through a comparison of the computed results with test data and other conventional methods. It is shown that the numerical results given by the proposed method are in well agreement with test results，and the proposed numerical method considering the creep effect can be used for evaluation of long-term behavior of reinforced earth structures.

Firstly the division of synthetic energy，the structural entropy of soil，the quantitative structure parameters of soil and the concept of exchange between entropy and energy are proposed. The framework of traditional soil mechanics in which homogeneous theories are applied to solve problems of non-homogeneous soil is changed，and the conception of structural entropy is discussed，which leads to a ration of many complex elements by the unified state of entropy. A quantitative parameter for soil structure characteristics also is provided，which is named entropy and energy exchanging parameter. The principle of macro and micro energy state exchanging will be especially emphasized and investigated.

Based on the Biot consolidation equations，the governing differential equations of the nonlinear coupled process of seepage field and stress field are given by introducing the function of permeability tensor with respect to stress tensor. Finite element method is therefore given based on those equations. Precise integration algorithm is applied to time discretion in finite element computation to decouple the coupled process. With the precise integration algorithm as time discrete method，the convergent speed，the computational precision and the computational stability are improved comparing with the time differencing methods. The effectiveness and computational efficiency of the algorithm are proved by project practice.

Based on the mechanics of fluids in porous media and the continuum mechanics，a continuum theory of multiphase porous media is developed to analyze the propagation of elastic waves in a porous medium saturated by a mixture of two immiscible，viscous，compressible fluids. The behavior of porous media can be described by three equations of motion，two continuity equations of flow，and a supplementary equation that describes the constitutive relationships. A closed-form solution is derived for a fully coupled model considering the capillary pressure and irreducible/residual saturation，which demonstrates the existence of three types of compressional waves and one type of shear wave. The theoretical results are plotted and compared with the experimental data available in the previous studies. This solution is highly versatile in that it considers compression of the solid grain，compression of both pore fluids，deformation of the porous skeleton，and spatial damping. In addition，all the material parameters in this model are measurable.

Based on the results of test，monitoring and analysis of the underground engineering of Xiaowan Hydropower Station in China，a generalized model for geology and construction process is established. By combination of computing schemes of uniform design method with basic mechanical parameters and initial stress field as basic variables，the three-dimensional elastoplastic finite element method is used to simulate the excavation of underground major plant considering the effect of excavation unloading，and the basic mechanical parameters and initial stress field are obtained by multivariate linear regression method. The coincidence between the back analysis and the testing data indicates that the obtained mechanical parameters and initial stress field are reasonable，and the uniform design method can be used in displacement back analysis of underground engineering.

By measuring the velocities of the P-wave and S-wave in three orthotropic directions including parallel and vertical directions to the stratum of the rock samples for slate，phyllite，mylonite and metasandstone，and based on the wave velocities of other rocks from the relevant studies，the anisotropic effect of wave velocity ratio of the P-wave and S-wave for most rocks is put forward. The anisotropic effect is controlled by the lithologic characteristics，and apparent for slate and phyllite，while not for the other two kinds of rocks，mylonite and metasandstone. The wave velocity ratio vertical to the stratum of the rock samples is usually less than that in parallel direction，and the relative increment of wave velocity ratio between the vertical direction and the parallel direction decreases as the wave velocity ratio in vertical direction gradually increases. By treating the rock as the transverse isotropic elastic medium and using numerical test of the wave velocity function，the property is theoretically validated.

Because tunnel construction inevitably disturbs stratum，ground settlement with different degree is generated resulting in unfavorable effect on safety of subway construction and surrounding environment，such as roads，bridges，underground pipelines and ground buildings in urban districts. So it is necessary to define guideposts of ground settlement scientifically to reduce or avoid unfavorable effect caused by ground settlement. Based on many in-situ investigations of projects，statistic analysis for measured data with fuzzy cluster analysis，and consideration of economy of engineering construction，the method and controlling value for defining ground settlement guideposts are given，which is important to guide tunnel construction.

Dongguashan Copper Mine is the deepest metal mine which has strong rockburst hazard in China. A microseismic monitoring system is established to monitor and predict rockbursts in real time in the mine. Therefore，the optimization of distribution of microseismic network is carried out. The characteristics of rockburst distribution caused by simultaneous excavation of multi-panel and multi-stope are analyzed to determine the monitoring area. Many schemes of distributions of microseismic networks are designed in terms of the monitoring area，the underground drifts and technical characteristics of the seismic monitoring system in the mine. The errors of source location and system sensitivities associated with these schemes are calculated. The optimum distribution of the microseismic network is gotten by synthetic analysis of the calculation results，engineering conditions and economical efficiency. After the system is established，some in-situ tests are made to measure the errors and sensitivities，and the results confirm that the optimum distribution meets the requirement of seismic monitoring in the mine，and the monitoring data are reliable and valid.

The constitutive model of rock mass remains one of the most fundamental theoretical problems in rock mechanics to be solved. Based on the experimental results of the fractured rocklike materials，the localized progressive damage model is built. In this model，the representative volume element(RVE) is divided into the elastic zone and localized shear band according to the failure process and failure mechanisms of the fractured rocklike materials. The deformation process of the localized shear band is divided into cohesion weakening and friction strengthening phases. So，the emphasis in establishing the model is placed on the failure essence of the fractured rocklike materials，that is to say，the phases of cohesion weakening and friction strengthening should be exerted in tandem，which is discovered by the experiment. Moreover，in this model the processes of cohesion weakening and friction strengthening are represented by the damage variable which is defined in virtue of the relative sliding displacement of the shear band that represents the characteristics of the progressive failure process of the RVE. Furthermore，the chain model in localized band and homogenization method are adopted to combine the meso characteristics with the macro mechanical properties in this localized progressive damage model. Finally，based on the experimental results of M. Yumlu and M. U. Ozbay，the localized progressive damage model is validated. The result calculated through the localized progressive damage model agrees well with the experimental result，which proves the model is right.

Four kinds of plants including Myrsine，Vitex negundo，Bauhinia，Pogonatherum paniceum，grew on according to different weathering degrees of bedrock，and were selected to measure pull-resistances，mechanical characteristics of single root and biological indexes by the in-situ pull-out experiment. The purpose is to study the mechanical characteristics of interaction between the root system of plants and rock for rock slope protection. The results indicate that the pull-resistance of shrub is impacted by configuration of the root system，maximum pull-resistance of single root and the amount of roots under stress. The maximum pull-resistance increases with root diameter increasing，and there is a good power function relationship between them. The relationship between pull force and tensile stretch of single root changes with different vegetation types. Furthermore，the maximum tensile stretch varies with different root diameters. The pull force-tensile stretch of Bauhinia jaberi oliver and Vitex negundo is of linear relationship，which fallows Hook¢s law，while that of Myrsine africana is of logarithm function relationship. The maximum tensile stretch of Bauhinia jaberi oliver and Vitex negundo is declined with increment of root diameter. The relationship between the maximum tensile stretch and root diameter appears a unimodal curve. If the diameter at ground height(DGH) or plant height is similar，the pull-resistance of plants increases with bedrock weathering degree. If the rock weathering degree is similar，the pull-resistance and some factors such as DGH，plant height and subterranean biomass show positive correlations and present exponential function relationships. However，there is no obvious mathematic relationship between biological factors and the pull-resistance of Pononatherum paniceum，and the mechanical effect between Pononatherum paniceum and bedrock is not distinct. As a result，the research result can provide reference to the structural design of eco-engineering for rock slope protection(EERSP) and selection of vegetation type.

Natural soils are often structured because of weak bonds between their particles and subjected to many different stress paths in the field. By conducting experiments on structured soils with changes in stress paths，the mechanical behavior can be investigated on which the establishment of proper constitutive model for structured soils is based. The results are presented for drained and undrained triaxial tests on structured soil specimens under different stress paths. The soil specimens are artificially prepared in the laboratory. Under different consolidated stress conditions，the specimens are gradually loaded axially to failure while the confining pressures are constant，increase or decrease step by step. The mechanical properties，strength properties and deformation mechanism of structured soils are investigated and analyzed.

In recent years，with the construction of the expressways，large-scale hydro projects and deep foundation pit projects，accidents arising from cut are more and more serious，especially in West of China，where ground surface is mostly covered with colluvial soils，and the human activity has already become the main inducing factor on geologic hazard. In order to understand the fundamental mechanism of cut-induced landslides in colluvial slope and to clarify some important characteristics of slope，in-situ cut tests and synthetic field monitoring method were carried out on a typical colluvial slope in Guizhou Province，China. The results demonstrate that most of accumulation landslides caused by cut are shallow drawing slope failures. The deformed zone lies within the top soil layer of 4 m，the deformation amount of slope surface is the biggest，and the deformation form is relaxation，which is reduced from the top to deep part of slope gradually. The alert height of the free face is 3 m in such slope. When the free face exceeds 3 m，proper protecting measures are necessary. Under the influence of strong rainfall，the uncovered colluvial slope after cut easily leads to collapse accident.

Rock failure induced by thermal stress is called thermal cracking. It is the result of thermal and mechanical coupling. Based on the basic theory of rock deformation and thermodynamics，considering the heterogeneity and the coupling of thermal and mechanics，a numerical model，RFPA2D-thermal code，is proposed. With this model，the temperature and stress fields can be determined. The most important is that the failure process of rock induced by thermal or external stress can be simulated. Using this numerical model，the failure progresses of a rock sample with an inlaid grain was modelled during the change of temperature. It turns out that during temperature increment，if the thermal expansion coefficient of the inlaid grain is larger than that of the surrounding media，radial-cracks will be generated in the surrounding media，and theta-cracks emerge if the thermal expansion coefficient of inlaid grain is smaller than that of the surrounding media. The results agree well with the experimental results. The RFPA2D-thermal model provides a new method for analyzing the thermal cracking of rock samples in microscopic view.

The coefficient matrices are called the Lagrange matrix，and associated with the system of linear equations. The system of linear equations is referred to the Lagrange equation set in this study，which is deduced by the Lagrange multiplier method，and is in general symmetric indefinite matrices. Solving such a system would encounter some intricacies if its leading principal submatrix，i.e. the stiffness matrix，is rank deficient. This is believed to be one of the main reasons that many programmers would unwillingly give up the Lagrange multiplier method but select the penalty function method. Based on the Sherman-Morrison formula and the conventional LDLT decomposition for symmetric positive definite matrices，a robust direct solution is proposed，which is efficient and particularly suitable for parallel computation. As a paradigm，the proposed procedure is used to solve the set of linear equations derived by the element-free Galerkin method(EFGM) with the moving least squares interpolation.

Rock masses containing coplanar close discontinuous joints are commonly found in nature，and their failure mechanism and strength strongly depend on the properties of joints and rock bridges，which are defined as the areas between joints. Several shear failure criteria of the rock mass are viewed and compared，and their weaknesses are pointed out. The mechanical behaviors of brittle rock mass containing coplanar close discontinuous joints under shear condition are analyzed，and the failure mechanisms of the rock mass are proposed. The rock mass may fail in three ways，failure in tension，failure in shear，and failure in mixed tension and shear. A modified criterion of failure strength of the rock mass is proposed for failure in mixed shear and tension. The equation of the shear strength contains the properties of geometry and mechanics of joints and rock bridges. Shear initiation angle as a new parameter is introduced firstly and also is contained in the equation. The failure mechanism can explain the phenomenon in direct shear test，and the calculated results according to the modified criterion of failure strength agree well with experimental results.

On the background of reinforcement engineering of the left-bank of Lijiaxia Hydropower Station，two models，one of which is reinforced by prestressed cable and the other is not reinforced，are compared by geomechanical model experiment techniques. The stability and reinforcing effect on wedge-shaped rock with double sliding surfaces in the slope are researched. The method of simulating complex rock slope and prestressed cable are given. Some results，the variety of relative displacement and absolute displacement of the wedge-shaped rock with double sliding surfaces of the two above models，the prestressed force variation rules of cable with time，the axial force variation rules of anchor cable with time，and the deformation and damage characteristics of cable in different areas of slope are presented. Based on the results，the safety factor of two models are calculated and analyzed. The calculated results show that the safety factor of reinforced slope is 1.4 times higher than that of not reinforced one. Finally，the reinforcement effect on the wedge-shaped rock with two sliding surfaces in the slope reinforced by prestressed cable is summarized.

The deformation feature of deep shaft coal roadway is analyzed，and the reason for many kinds of support failures is studied. The coupling balance supporting principle of inner and outer structures is put forward for these roadways. For surrounding rock control of deep shaft coal roadway，it is necessary for the high strength supporting structure to take part in the redistribution of stresses in surrounding rock after excavation，so as to decrease the strength damage of coal. Thus the stable bearing structure can be formed rapidly around the roadway，and the area of plastic fluid zone of surrounding rock can be reduced. The industrial test shows that the supporting principle is correct.

Bolt is widely used in slope engineering，tunnel，and large cave supporting as well as restoration of engineering structure. It can improve the strength and stability of ground，rock mass，and other structures. The traditional steel bolt has some disadvantages，such as easy corrosion，heavy weight，and difficult operation. Glass fiber reinforced polymer(GFRP) is impervious to chloride ion and low pH chemical attack，and its tensile strength is much larger than steel while with lighter weight. Those advantages make it a better alternative in some fields of engineering. To utilize GFRP bars as rock bolt，some aspects of its behavior，such as bond strength in mortar，bearing capacity，and bond stress distribution along its interface，have to be examined. This paper presents the research on bonding behavior of anchor bolt made of GFRP bar，and concrete block is used to model rock mass in laboratory. The modified pull-out tests were conducted on selected GFRP bars and compared with steel ones that were grouted with mortar in concrete blocks. The diameters of the GFRP test samples are 10，13，16 mm respectively，and the steel one is 25 mm. There total 24 samples are tested. The surface of the GFRP bar is sprayed with sand and wound with fibers. The compressive strength of concrete which is used to simulate the rock mass is 58.3 MPa；and the compressive strength of two kinds of mortars are 41.5 and 55.5 MPa，respectively. According to the results，bond characteristics of mortar grouted GFRP rock bolts such as failure modes，bearing capacity，critical bond length，average bond strength，and comparison with steel bolt were evaluated. The research will give a support to the application of GFRP bolt.

Combined with water gushing in pit，the laboratory model test research is carried out. By comparison between the parameters before and after the test，the development regulation of physico-mechanical parameters of the substratum of pit is found. The cohesion and modulus of compression of the substratum are deeply reduced after water gushing in pit，but the internal friction angle of the substratum doesn¢t change. According to the results of the test，when the head pressure of confined aquifer is equal to the earth pressure of the super stratum，the gushing in pit doesn¢t occur. So this paper points out the disadvantages of pressure balance method，traditional judgment method of water gushing in pit. Based on the theoretical analysis of the test results，considering the cohesion force component of the shear strength，the judgment method of gushing in pit is quantified for the first time and is compared with engineering practice. The results show that the traditional judgment method of water gushing in pit is overestimated when it is used to design the pit in soft soil.

The distinguishing index and grading standards of expansive soil are recommended by Specifications for Design of Highway Subgrades(JTG D30–2004). Its feasibility for expansive soils in the middle area of Anhui Province is discussed，and the correlation of three distinguishing indexes and consistence of classification grade are analyzed. The analytical results indicate that the standard absorption moisture possesses the better sort feature，but the classification grade is obviously higher according to the above specification，and the free swelling ratio of expansive soil in the middle area of Anhui Province is lower. On the foundation of above research，the grading standards for the expansive soil in the middle area of Anhui Province is suggested，and the classification result can achieve better unanimity according to the suggested standards. Finally，verification analysis is carried out by consulting the content of colloidal particle less than 0.002 mm and the content of montmorillonite. The analytical results illustrate that the suggested standards possess the better applicability for expansive soil in the middle area of Anhui Province.

Shaking table test is an important method to study earthquake resistance of engineering structures. The design process of a large-scale soil laminar shear model box，which is indispensable in shaking table test，is described. The advantages and disadvantages of all sorts of the soil model boxes used in the shaking table test are compared. Based on the comparison and analysis of seismic response of the prototype soil deposit of semi-infinite free-field，a large-scale laminar shear model box，which can replicate prototype soil layer boundary conditions，is designed. The internal dimensions of the model box are 3 m in length，2 m in width and 1.8 m in height. The model box consists of fifteen rectangular，laminar rigid frames can well simulate the boundary conditions of prototype soil layer. The developed laminar shear model box lays a firm foundation for the success of the test and can also be adopted in other tests for seismic geotechnical problems。

The testing result of standard absorption water content strongly depends on the initial moisture content，structural property，and moisture elimination and absorption procedure of the samples. It is important to study the standard absorption water content with different sampling methods. The research results show that the value of the undisturbed and remolded samples is greater than that of air-dried and oven-dried samples. A certain linear dependence relation exists between the standard absorption water content of the undisturbed sample and that of other three sampling methods，and the square of correlation coefficient is 0.94–0.97. After being modified，the testing results of other sampling methods can substitute for those of the undisturbed samples.

Compared with the other methods in in-situ stress measurement，the method of CSIRO cells is more accurate and can get the three-dimensional stresses. Professor Cai Meifeng improved the accuracy of cells and the confining pressure formulation. But now，there are some errors created in the actual operation，circuit，temperature compensation and the confining pressure formulation. With comparing two kinds of cells，it is found that 13-wire cell is better in circuit and 15-wire cell is more accurate in temperature compensation. The confining pressure formulation is analyzed，and it is pointed out that the formulation derived by Professor Cai Meifeng didn¢t consider the restriction effects of the rosin layer，so it is not accurate enough in practice.

Based on the different compression behaviors of natural and reconstituted calcareous sand，it is presented that the additional void ratio can cause particle breakage of natural calcareous sand. Within the frame work of critical state soil mechanics，an elastoplastic model including the state parameters and cap yield surface is developed. A unique set of parameters for a given sand is needed over a full range of densities and stress levels. By making comparisons of predictions with triaxial test，it is demonstrated that the model provides satisfactory simulation of strength and dilatancy of calcareous sand.

On the basis of in-situ survey data，the displacement of anti-slide pile top is predicted using the gray prediction theories of GM (1，1) model. Furthermore，according to the definition of very slow speed of landslide by D. J. Varnes and the rule of deformation stability of in-situ loading test，the critical speed of anti-slide structure stability is put forward. Then，by combining the gray prediction equation of displacement of anti-slide pile top and the critical speed of anti-slide structure，the stability time of anti-slide structure is solved，and a new method for stability time prediction is set up for anti-slide structure.

Based on the discussion on some problems existing in the tunnel design and construction，a new method to build an automatic analysis platform for tunnels is proposed，which is based upon lots of numerical test results，expert experiences and the powerful artificial neural network method. In the platform，many factors impacting on the stress and deformation fields of the surrounding rock masses can be considered，such as the size of underground tunnels，the overburden，the mechanical parameters of rock masses，the initial stress and the main fault nearby，etc.. The proposed numerical platform has been compared with large scale numerical analysis and field measurement，with the error of less than 10%–20%.