With the development of underground engineering, high geothermal problem has become one kind of important engineering problem for deep tunnels and some tunnels with complicated geological environment. And it has attracted more and more attentions of scholars around the world. It is necessary to study the temperature distribution of the tunnel for solving the frost heaving problem of tunnels in cold regions, high geothermal temperature around the tunnel and the problem caused by tunnel fires. In this paper, a two-dimensional steady state thermo-elastic problem of tunnels is investigated by using theoretical method. The tunnel has a finite length. It is located in a high geothermal surrounding and subjected to axisymmetric temperature gradient due to excavation. The earth pressure is also considered in the analysis. The shape of the tunnel is assumed to be circle. Employing dimensionless and series solving methods of differential equations, analytical solutions of temperature, displacement and thermal/mechanical stresses have been obtained. Based on the present analysis, an illustrative example of tunnel containing the lining and the surrounding rock is numerically studied. And it is obtained the reasonable calculated thickness of the surrounding rock causing by the tunnel excavation. The conclusions provide an important theoretical basis for the thermal insulation in the tunnel construction and operation process.

The rheological action of the soft rock-soil could be accelerated by the dynamic loading, which induces more geotechnical engineering accidents and geologic disasters. The samples of marine deposit soft soil are collected in Xiamen, and the dynamic rheological characteristics of dynamic stress-strain, rheological strain-time and rheological displacement are tested under the different frequencies of dynamic loading of sinusoidal variation using dynamic-triaxial device and remodeled samples. The influence on rheological characteristics of marine deposit soft soil is analyzed under different frequencies of dynamic loading. The experimental analysis indicates that when the frequency of dynamic loading is low, the rheological dynamic characteristics sensitivity of marine deposit soft soil is obvious, and the rheological distortion is quick. But when the frequency of dynamic loading is high, the rheologic dynamic characteristics sensitivity of marine deposit soft soil is not obvious, and the rheologic distortion is slow. The research results have theoretical and actual significance for us to open out the dynamic rheological characteristics and the rheologic dynamic mechanism of bursting out geologic disaster under dynamic loading with different frequencies.

Y-shaped vibro-pile is a new type of pile, compared with the traditional circular pile, the Y-shaped cross-section pile increases the contact area of the pile and soil, and thus increase skin friction and the bearing capacity. Due to the particularity of the pile cross-section, when Y-shaped pile is driven by pipe with vibration, different area of Y-shaped section have varying degrees of compression on the soil and its skin friction distribution trait is complicated than circular pile. Simplifying Y-shaped pile skin friction as rectangularly distributed along the pile length direction and uniformly distributed along the section perimeter direction does not match with the actual and the engineering experience also shows its inappropriate. Firstly, combining the cavity expansion theory and the analytical equations of Y-shaped section to deduce the nonuniform distribution, it is shown that the maximum skin friction is 1.24-1.75 times larger than the minimum skin friction at the same cross-section; the influences of three variables R, θ, L of Y-shaped pile on skin friction are also analysed. The total skin friction can be calculated by quadraturing the skin friction along nine integral regions of the Y-shaped section and the pile length direction，combined with the tip resistance，the ultimate bearing capability is obtained and consistent with the data of static loading test.

On the basis of a series of indoor shear stress relaxation tests for unsaturated remolded expansive soils by using a quadruple load equal strain-controlled direct shear apparatus，the shear stress relaxation characteristics of this kind of soils were researched. Many useful conclusions are obtained. The results show that shear stress relaxation curves under different initial conditions are all incomplete attenuation type; but the shear stress decreased gradually and eventually tending to stable values. The relaxation curves can be clearly divided into three stages, i.e. the instantaneous relaxation stage, attenuation relaxation stage and stable relaxation stage. Shear stress-strain curve at different moments is nonlinear under different initial conditions, which indicates that expansive soil in Nanning is nonlinear, indeed bomb, sticky, as well as plastic. The conclusions show that the soil is the higher the nonlinear degree of the rheological properties of expansive soil with higher the moisture content, or the smaller the vertical load, or the greater initial strain, or the longer the time. Based on the analysis of tested results, an empirical shear stress relaxation equation of Nanning expansive soils under the condition of direct shearing has been established by improving the linear relationship between logarithm of shear stress and time. The regression curves of empirical relaxation equation are in good agreement with those of the observed data. The strain level of stress relaxation was taken into nonlinear empirical models. It intuitively reflect the nonlinear stress relaxation properties of Nanning expansive soils. The model is more corresponded with the actual engineering, so as to provide a theory for analytical calculation of nonlinear stress relaxation problems of expansive soils.

An infinite two-layer plate on viscoelastic half-space foundation subjected to moving loads is employed as the model of pavement structure. The dynamic Green’s function of the pavement under the unit impulse load is developed using a triple Fourier transform. Based on the superposition principle of linear system，the analytical solutions of the steady-state displacement and stress responses are then derived by combining the generalized Duhamel integral with the Green’s function. The adaptive Simpson numerical algorithm is successfully used to calculate the multiple integral of singular and oscillatory function, and transfers the solutions from the wavenumber-frequency domain to the time-space domain. The vibration characteristics of the pavement under moving constant and harmonic loads are analyzed through some numerical examples; and parameter studies then follow to show the effect of plate thickness and elastic modulus of plate material on the dynamic responses of the pavement structure. The results give an insight into the vibration regularities of pavement under moving loads, and may have important theoretical significance and reference value for the design and construction of pavement.

Aiming at the monitoring and test of rockburst, the uniaxial compression tests and acoustic monitoring of rockburst in straight-wall-top-arch roadways(tunnels) were carried out and on this basis rockburst splitting and shearing were discussed.The results show that the failure surface of surrounding rock is rough and showing thin splitting block and the whole sample is also showing a distinct splitting rockburst; wave velocity can reflect the rock damage evolution process; and wave velocity from constant to lessening can be used as the dot of critical damage for rockburst prediction which can be achieved by monitoring velocity variation; surrounding rock internal development and changes can be a very good grasp by monitoring the waveform, especially waveform sparse and periodic increase; combination of qualitative and quantitative monitoring by the comprehensive monitoring of sound velocity, waveform sparse and periodic increase can timely and accurately predict rockburst in order to protect personnel and equipment safety; comprehensive expression of splitting rockburst is developed by the stress intensity factor and the ratio of rock's compressive-tensile strength and the numerical value corresponding to rockburst intensity standard of stress intensity factor are developed; stress intensity factor criterion of splitting rockburst is between 0.27－0.80(R=10－30 ); shearing failure condition will be satisfied with the increase of stress intensity factor and the main failure form will develop in the direction of shearing failure.

Through the confining pressure unloading experiments, the dilatation characteristics of salt rock under different triaxial stress states unloading pressure, and the relationship between dilatation and unloading method are researched. The results show that: (1) There is a logarithmic relationship between volumetric expansion of capacity and deviatoric stress during unloading confining tests. (2) Initial confining pressure value hardly effects the dilation of salt rock. The growth of axial pressure can promote the dilation, and make the accelerated-expansion-point appear forward. Meanwhile, the corresponding deviatoric stress linearly increases with the axial pressure. (3) With the increase of deviatoric stress, the expansion coefficient of salt rock (ratio of lateral strain to longitudinal deformation) will increase linearly at the beginning; and then exponentially.

Through the anti-explosion model tests, the deformation and steady state of large span unlined tunnel and bolting and shotcrete lining supported tunnel under explosive plane wave are studied. This paper introduces the principle and method of model test. Based on the test data, the stress characteristics of surrounding rock, deformation behavior of tunnel wall, and the fracture morphology as well as bearing capacity of tunnel are analyzed. Research shows that under the design condition and overload condition, when tunnel supported by bolting and shotcrete lining, vertical stress in side wall, acceleration peak value of tunnel vault, peak and residual value of the displacement of tunnel vault, and peak value of hoop strain on tunnel wall are less than unlined tunnel. After overload test, unlined tunnel is damaged badly and loss of bearing capacity; but bolting and shotcrete lining supported tunnel is damaged slightly; the bearing capacity can be increased by 60%.

Industrial by-product resource is an effective way to solve the environmental pollution of industrial by-product. Clay is stabilized by fly ash mixed with lime or blast furnace slag mixed with lime, respectively. The effects of binder content, curing period on the unconfined compressive strength, pH value, and degree of saturation of treated soils are investigated by a series of laboratory tests. Test results show that the unconfined compressive strength of stabilized soils increases with the increasing of binder content and curing time. A unique negative exponential function well adapts unconfined compressive strength of stabilized soils with a synthetical parameter, which represent the effect of binder content, curing period and degree of compaction. Fly ash mixed with lime or blast furnace slag mixed with lime can effectively enhance soil unconfined compressive strength properties. Lime is an effective alkaline activating agent, and the highly alkaline environment resulted from the lime can provide pozzolanic reaction conditions for industrial by-product. These results can provide a test basis for the design of stabilized soils by industrial by-product binders.

The rising of pore water pressure and decreasing of matric suction in the process of rainfall infiltration into slope is the main factor of slope failures .Numerical simulation method of critical slip field of slope considering rainfall process is proposed based on proposed unsaturated soil shear strength theory and water pressure field obtained by finite element analysis of saturated-unsaturated seepage. Thus, slope local safety factor and slope whole safety factor as well as the corresponding critical slip surfaces during infiltration are calculated conveniently and rapidly. This method has been applied to the stability analysis of two example slopes and the effect study of rainfall intensity, duration and strength parameter on slope stability. The results show that the critical slip field method could search for any shape of the most dangerous slip surface; and the safety factor is reasonable.

Particles’ breakage has an important effect on the macromechanical behavior of granular materials. An elastoplastic model combined with an experiential crushing equation is suggested for crushable granular materials based on Cosserat continuum, Hardin’s definition of relative breakage , which is used to quantify the extent of crushing, can be obtained from the crushing equation according to normal crushing stress. The internal length scale of Cosserat continuum theory is related to the average particle size of granular materials; and the evolution of which is computed by the relative breakage . Numerical examples focus mainly on the effect of particle crushing on the bearing capacity and localization of plastic strain. Numerical results illustrate that particles crush mainly in shear band, and shear band obviously becomes narrow and the equivalent plastic strain gradient increases when considering crushing.

Carbonation is one of the strength enhanced mechanism for lime stabilized soil. But there has many major problems need solution. For example, whether the long-term carbonation is always beneficial to its strength? If limed soil were not compacted tightly, how about was the carbonated effect of it? So, California bearing ratio CBR tests were performed to evaluated the influence of compacted degree on carbonated effect by preparation samples under curing before and after compacted conditional. And also, CBR tests were carried out to prove the long-term carbonation effect on the strength of lime stabilized soil by analyzing the strength variation of four kinds of initial water contents compacted specimens which were under immersion in carbonate solution and pure water separately. The results show that the CBR values of sample compacted after natural curing 90 days are significantly lower the strength of samples which compacted before curing, when their initial moisture content is 34.0%; the former CBR are about 12 times as the later ones. And, the CBR of samples immersion in carbonic acid solution 15 days are less than pure water immersion ones. But, the higher initial water content is, the smaller the influence is. For example, the initial moisture content is greater than 34.0%, the CBR values are obviously difference between them. In addition, it carried out unconfined compressive strength test under different soaking times, the results further evidence that long-term carbonation can reduce the strength of stabilized soil. Finally, thermo-gravimetric analysis tests are performed to the limed soil to determine the content of calcium carbonate and to evaluate whether or not there are degradation and migration after soaking in carbonate solution. And, it reveals the effect mechanism of different compactions and curing methods on the strength of lime stabilization by scanning electron microscopy photographs and pore size distribution curves.

An approximation model to evaluate the limiting soil resistance beneath the cutting curb during sinking of an open caisson is investigated, in which the shape and embedment depth of the cutting curb are considered. And then a typical slip line field for this problem is presented approximately with Prandtl failure mechanism; and the formulas of bearing capacity factors are derived for the plane strain problem and axisymmetric one of a circular open caisson, respectively. For the plane strain problem, the bearing capacity factor Nγ is composed of two parts: one part is caused by the tread of cutting curb; and the other one is the inclined plane, and the former, as well as the other bearing capacity factors, Nc and Nq, are identical with the results derived from Prandtl failure mechanism when the embedment depth of cutting curb is not considered. The embedment depth and width of tread and taper angle of the cutting curb exert a major influence on the limiting soil resistance. If neglecting these influence factors, the evaluated value of the limiting soil resistance would be significantly small. This study shows that the values of bearing capacity factors increase significantly with the increase of the embedment depth or taper angle of cutting curb. And it also shows that the taper angle has a more significant influence on the limiting soil resistance when the strength of soil is relatively high.

Before technical guideline of sludge treatment and disposal for municipal wastewater treatment plant [1]was implemented, tons of sewage sludge was directly poured into sludge lagoon in landfill, which took up designed landfill capacity of municipal solid waste. In order to restore storage capacity of landfill, treatment of sludge lagoon was undertaken. To investigate the feasibility of using vacuum preloading technique on sludge, two model tests were conducted. The experimental results showed that after vacuum preloading water content of sludge decreased sharply and its shear strength increased to 2-4 kPa. The consolidation coefficient of sludge displayed a nonlinear behavior in preloading process. Permeability and water content of sludge around prefabricated vertical drain decreased quickly in early stage, hindering consolidation of sludge away from prefabricated vertical drain. Therefore reducing spacing of prefabricated vertical drain could enhance treatment effect significantly. Pore pressure dissipation of sludge in preloading was different from that in soft clay, especially of the sludge distant from prefabricated vertical drain, which may reveal that pore pressure dissipation in sludge could not be explained by consolidation theory of Terzaghi. In vacuum preloading of sludge, intermittent inlet of boosted air could accelerate drainage rate in early stage; but overall its improvement was limited. Vacuum preloading method can be used as a technique of sludge reduction; but for the requirements of subsequent filling of municipal solid waste on the sludge lagoon, other in situ ground improvement methods should be adopted further to increase its shear strength.

The compaction and penetration tests of highly plastic clay, located between the dam core wall and cushion concrete in Nuozhadu hydropower station, are performed. The compaction mechanism and the influence of different construction technological parameters such as grain composition, filling thickness and compaction times, etc. are discussed by the field roller compaction and penetration test. On the basis of the test, the optimal technological parameters and quality control specification of the given project are found by contrast tests for which various detection methods such as compaction settlement, watering method and cutting ring are adopted. And field compaction and penetration quality control method of highly plastic clay is put forward; namely, differential settlement and compaction is given priority but construction technological parameters must be considered at the same time. The method may insure filling quality effectively and quicken construction progress. And it also can provide scientific data, standards for the quality control, quality check, quality evaluation of the projects for which highly plastic clay soil is adopted as filling material. It has significant applicable value.

Using the analytical method, vertical vibration characteristics of pipe pile in saturated viscoelastic soil considering mass-coupling effects are investigated in the frequency domain. Based on Biot’s dynamic theory, the expressions for displacement and stress of the saturated viscoelastic soil are obtained by using Novak’s layer method. The pipe pile is treated as the Euler-Bernoulli rod. By utilizing the continuity conditions between the soil and pipe pile, a general analysis method for the vertical vibration of the pipe pile in the saturated viscoelastic soil is presented; and the expression of the complex dynamic stiffness at the pile top is obtained. On the basis, the comparative analysis between the vertical vibration characteristics of solid pile and one of pipe pile in saturated soil is made. By using the numerical example, the influences of mechanical parameters of soil around the pile and inner soil on the dynamic stiffness factor and equivalent damping at the pile top are investigated. It is shown that the vertical vibration characteristics of solid pile and pipe pile have significant difference.

This study aimed to develop an appropriate similar material for weak surrounding rock mass which can be used in physical model test of tunnel surrounding rock mass stability. The weak surrounding rock mass of class IV has been chosen as reference prototype for our research. Five raw materials, namely, barite powder, gypsum, fine sand, laundry detergent, and water were used to produce the similar material. Direct shear tests, uniaxial compression tests and triaxial compression tests were performed to obtain strength characteristics and physico-mechanical parameters of the material, including cohesive strength c, internal friction angle ? uniaxial compressive strength Rc, elastic modulus E, Poisson ratio ?. Firstly, a large number of the above mentioned tests were carried out to analyze the impact of various proportions of each raw material on strength characteristics and physico-mechanical parameters of the similar material; thus selecting appropriate raw material proportion to simulate the weak surrounding rock mass of class IV. Secondly, strength characteristics and failure behavior of the similar material which had been developed with selected raw material proportion, is further studied by a large numbers of triaxial compression tests under various confining pressures. The results indicate that, either decreasing water content or increasing gypsum content can lead to an obvious increase in Rc, E and c, along with a slight decrease in ?. On the other hand, the mounting of fine sand content resulted in an increase of E and ?, while Rc value decreased. In addition, while gypsum content turned out to be the most important factor affecting the brittle and ductile characteristics of similar material; water content affected the strength of such material significantly. The results also show that the developed material presents brittleness under low confining pressure, and becomes more ductile with the increase of confining pressure. Furthermore, failure data of the material are smaller than that calculated from linear Mohr-Coulomb failure criterion and slightly higher than that of nonlinear Hoek-Brown failure criterion. However, similar material obeys far better the Hoek-Brown criterion. The results of this study will be very useful for future research on tunnel surrounding rock mass stability in physical model tests, as well as in numerical simulations.

The initial distribution of normal stresses over the slip surface is assumed, which is then modified by a Lagrangian function involving two parameters to satisfy the complete equilibrium conditions of the sliding body. Reliability of the proposed method was verified and relation between pseudo-static coefficient under blast seism and safety factor of on slope was explained by using calculatiexamples. Computed results in some engineering cases show that the horizontal and vertical dynamic loads as well as their combined dynamic load make the greatest impact on the safety factor of slope stability. When horizontal dynamic load pseudo-static coefficient is added 0.05 from 0 to 0.3, the safety factors are reduced 6.65% -23.54 %. When vertical dynamic load pseudo-static coefficient is added 0.05 from 0 to 0.3, the safety factors are reduced 1.18 % -2.52 %. The combined load action direction has also some impact on the slope stability.

The stability of colluvial slopes in high-altitude mountain areas, three rivers sources regions, northwestern Yunnan is one of the main problems in road construction. Model test is one of the most effective means for investigating the factors for the slope stability. Based on the theory of similarity and the definition of safety factor of the slope, a range of tools are used to transform the model test materials to reach the strength similarity requirements. A series of model tests were carried out, which reproduced the real conditions for the failure of colluvial slope. The model test results can give references for geotechnical designers and researchers. The slope angle when the slope fails increases by about 42%-100%, the cohesion increases by about 50%-120%, the internal friction angle increases by about 6%-8% when model test material changes from loose state to more dense state. The results show that when material density increases the strength increases and the slope stability increases; thus slope angle also significantly increases when slope fails. When water content of the material increases and the material is nearly saturated under rainfull, the cohesion decreases by about 70% and the internal friction angle decreases by about 7%. It is indicated that the material softening by infiltration is the most fundamental factor for the stability of colluvial slope.

Regarding the soil around the tunnel as homogeneous, continuous, isotropic, saturated and elastic medium, the conformal mapping method is applied to transform the considered region in the physical plane into concentric ring region in the image. The control equation for dissipation of excess pore water pressure is established based on Terzaghi-Rendulic theory of two-dimensional consolidation when the lining is impermeable. The analytical solution for dissipation of excess pore water pressure is obtained using separation variables method; and the formula for consolidation settlement is got according to the theory of elasticity. Combined with an example, consolidation settlement of ground surface is discussed considering disturbance degree of soil, soil’s coefficient of permeability, soil’s modulus of elasticity and the depth of tunnel. The results show that there is a proportional relationship between the added value of consolidation settlement and the variation of initial excess pore water pressure in the outside of tunnel. And the greater the disturbance degree is, the larger the consolidation settlement is. The greater the coefficient of permeability is, the faster the consolidation settlement is. There is no relationship between the coefficient of permeability and the final value of consolidation settlement. The larger the modulus of elasticity is, the larger the final value of consolidation settlement is. The deeper the tunnel is, the longer the time of consolidation settlement is, and the larger the final value of consolidation settlement is.

Pressure plate tests and double-ring infiltration tests are carried out for typical undisturbed strong and medium expansive soil and rock of the middle-route of South-to-North Water Transfer Project. According to the soil water characteristic curve and test results, the water-holding characteristics and its influence factors of different expansive soils and rocks are comparativly studied; and the variation of water volume change coefficients are calculated and analyzed. On that basis, the change characteristics of permeability coefficient and its nonlinear relationship with matric suction are discussed; and the infiltration characteristics and rules of expansive soils and rocks are summarized. The results show that, water-holding characteristics are influenced by the physical properties, mineral composition and structure characteristics of expansive soils and rocks. The sample with stronger expansion potential, higher fine grain content and smaller pore structure has lower dehydrated rate. Permeability coefficient and water volume change coefficient decrease with the decrease of the moisture content; and these parameters are influenced by dry density and expansion potential, which also have power function relationship with matric suction. The research results can provide calculation parameters and theoretical basis for the engineering construction.

The typical soil of deep foundation pit in the Yellow River alluvial plain is clay and silty clay. These two kinds of soils have rheological characteristics. The supporting structure deformation and internal force is time-effected when excavating in this soil. In order to master the trend of each control index, a soil visco-elastoplastic model should be developed. Based on the data of soil laboratory test in Jinan Provincial Capital Culture and Art Center deep foundation pit, the visco-elastoplastic second order nonlinear Newtonian fluid model is given. And the relationship between visco-elastoplastic model parameters and test data is built. First, the constitutive model of incremental form is built. Second, the visco-elastoplastic model is secondary developed in FLAC. Lastly, we use this model to analyze the lateral displacement moment and anchor internal force of foundation pit supporting structure. Based on this test, the model precision is proved. A case study shows that, the lateral displacement change is increased gradually with the increase of time; but the early increase is larger and the later deformation tends to be stable. The change of supporting structure moment and anchor internal force is increased at first then decreased in a small amplitude in contrary to the lateral displacement.

It is obtained the strata movement law under shield tunnelling construction engineering through similar material model test to monitor the curves over time that the different strata settlement trough and horizontal displacement at the same time taking the No.202 tender of No.2 line in Dalian city subway project as the studying object. The results show that the vertical displacement change of the monitoring points for the different strata can be fitted negative with exponential function. The ground strata disturbance has been produced because the first constructing tunnel and resulting as the ground softening; and the surface settlement of the two tunnels is obviously superimposed larger settlement. The existed underground structures or pipelines will prone to cracks subjected additional shearing when tunnel excavating, so that must taking effective protective measures.

Based on compaction test of different gradations and different moisture contents of coarse-grained soils, the compaction characteristics and fractal feature of coarse-grained soils are studied. The results show that the maximum dry density of coarse-grained soils would increase with the increase of coarse grained content in gradation. The maximum dry density reach the maximum value as the coarse grained content is 70%; while it would decrease with the increase of coarse grained content in gradation as the content is more than 70%. The particle size distribution of crushing granular has a good fractal feature. The crushing fractal dimensions are between 2.279 0－2.892 2; higher than that before test. Under the same gradation condition, the crushing fractal dimension of coarse-grained soils increased with moisture content. The increase amplitude is obvious when P5 is larger than 50%. A good linear regression relation exists between crushing fractal dimensions D and broken rate Bg. Difference value of the granularity fractal dimension before and after compaction can show the crushing degree of coarse-grained soils objectively. Coarse grained content and moisture content are two key factors affected on particle breakage; but the influence of coarse grained content is more obvious.

In the research on negative skin friction on pile, the pile-soil displacement is the key point concerned. As a mature flow test technique, the particle image velocimetry(PIV) is gradually used in the field of geotechnical tests. By applying PIV technology in the model test of negative skin friction on pile, some defects of traditional displacement measuring technique, such as cannot obtain displacement field, will be improved. Aiming at the characteristics of test, a testing box was designed which included steel plates and organic glass plate. The soil surface load was simulated by jack and load board. Settlement of each soil layer, settlement of pile and axial force were measured in the test; and the displacement field around the pile base was measured by PIV technology under various stages of heaped loads. The test results show that the settlement measured by PIV technology is consistent with the settlement measured by traditional technology. The results of PIV analysis can intuitively reflect the additional settlement caused by the negative skin friction on pile. In addition, influence scope of soil displacement caused by the settlement of pile is analyzed. The analysis results show that the vertical influence scope is about 1.75D (Disdiameter) and the horizontal influence scope is no more than 1 D. At last, a summary is made about the application of PIV technology to this model test, and some issues for future study are put forward.

Based on the Coulomb's earth pressure theory hypothesis that active earth pressure against the back of retaining wall is due to thrust force exerted by a sliding wedge of soil between the back of the wall and a plane which passes through the bottom edge of the wall and has an inclination of θ, a formula of active earth pressure is proposed, which considers the cohesion force on the sliding plane, the adhesive force between soil and the retaining wall, tension crack appears on the surface of cohesive soil, the strip surcharge; and the explicit solutions of critical rupture angle are given. When continuous uniform load acts on the back of the wall or without considering the situation that tension crack appears on the surface of cohesive soil, it can be solved by the same method with zeroing the distance from the strip surcharge to the coping and that the calculation of crack depth. Studies have shown that the calculation result of earth pressure based on specification is small, as the influence of strip surcharge on critical angle of rupture doesn’t count. The formula has a wide range of application, especially for the case that the strip surcharge acts on arbitrary position behind the wall. It has a certain practical value for the design and calculation of retaining wall in practical projects.

The traditional definition of the ground loss parameter is redefined and incorporated on to analytical solutions to predict the ground deformation in different cases of over-shaped or under-shaped in pipe jacking. The gap parameter g is improved based on Mindlin’s solution, so as to take account of the friction force between pipe and soil. Based on the excavation of soil disturbance around the partition, Loganathan soil deformation formula is amended.The improved gap parameter g is substituted into the amending formula to calculate jacking distances at different soil deformation; and then the surface dynamic change is obtained in top tube of the process of measuring. The case study shows that the results are in good agreement with the observed data.

When drilling in soft and weak rock, the drilling is difficult to form and collapses frequently. To solve this engineering problem, based on the assumption that the rock cohesion weakens linearly along the plastic zone, the elastoplastic analysis of surrounding rock of drilling was completed and the secondary stress, displacement and plastic zone expressions of distribution are obtained. Gained self-defined rock mass cohesion by using FISH language that embedded in FLAC3D software. The numerical simulation analysis of elastoplastic distribution of rock around drilling was done. Compared to the original ideal M-C standards, the contrast results indicate that the theoretical calculation is correct. Theory and numerical simulation results show that: The plastic zone radius formula (e.g. fixed Fenner solution) that based on ideal elasticplastic model is a special solution when cohesion co equal to cs. After considering the cohesion weakening and residual cohesion, the plastic zone radius is 1.4 times as big as fixed Fenner solution. The numerical simulation shows that the maximum tangential stress in surrounding rock of drilling present to approximately 2.9 times drilling radius from drilling center; the stress concentration factor is less than 2. When under the same in-situ stress conditions, the plastic zone radius expand obviously after considering the cohesion weakening. Through analysis it is gained that the best drilling reinforcement radius is 3 times of the drilling radius; these achievements were applied to a drilling engineering of a certain coal mine in China.

Shear stress distribution in anchorage interface of anchor is the attention points of anchor design. It directly affects anchoring effect. Shear stress in anchorage interface will cause larger strain gradient in rock and soil near anchorage interface. But the strain gradient is not considered in classical elastic theory which is used to analysis shear stress in anchorage interface. Bending curvature is introduced into couple stress theory which considers the effect on the deformation characteristics of the bending. The finite element calculation model for plane strain problem was build up based on couple stress theory. For tensile-type anchor，shear stress in anchorage interface and the boundary layer effect near anchorage interface and scale effect of couple stress were studied. The results of couple stress theory are compared with the results of classical elasticity theory. The results show that the shear stress and shear strain near anchorage interface in couple stress theory are smaller than that in classical theory，especially at the peak of shear stress. The shear stress on interface is not continuous. But shear strain abrupt change on interface has been improved; and a transition region appears near the interface. The characteristic length decreases; transition region becomes smaller; but strain gradient becomes larger. The influence on shear stress distribution in anchorage interface of the second shear modulus is not obvious.

To analyse the settlement characteristics of pile-plank structure in soft soil subgrade, the centrifugal model test is used to imitate the pile-plank subgrade with different preloading times about six moth and twen-four month. It is shows that the settlements of pile-plank subgrade mainly happen during construction in which the proportion of settlement will exceed 80% when the preloading time is more than 6 months. Whether the settlement of pile-plank subgrade will rebound or not during unloading time is related to the soil properties and preloading time. Overload preloading can significantly reduce post-construction settlement which can be reduced 70% for twen-four month to 6 nonth of preloading time. During construction of pile-plank structure subgrade, pile foundation exists negative friction and neutral position change is a dynamic process, ratio pile length between 0.47~0.7.

The removability and stability analysis of rock block are carried out independently in the classical block theory which tacitly approves the nonremovable block being absolutely stable and thus skips the stability analysis. However, in the practical engineering project, the “rock bridge” preventing the movement of rock block may crack, resulting the sliding of the nonremovable blocks. The likelihood of the cracking under gravity would increase with the size of block. This paper proposes a stability analysis method considering the cracking of the rock bridge. The nonremovable blocks are no longer assumed to be absolutely stable. When calculating the block stability factor, this method integrates the shear resistance of the rock bridges into the anti-sliding force of the block. Firstly every possible sliding surface and the intersection line of fractures are listed. Then the rock bridges damaged along each possible moving direction are determined. Afterward, the stability factor along each direction is calculated based on the Mohr-Coulomb yield criterion. The minimum stability factor is selected as the actual stability factor of the block and the associated moving direction is considered to be the most possible moving direction of the block.

The hydraulic fracturing and stress relief measurement data of North China was collected mainly from “Fundamental database of crustal stress environment in continental China”. The entries of in situ stress data are 1 017. The characteristics of macroscopic stress field in North China and study regions are investigated. The results are as follows: (1) The maximum horizontal stress and minimum horizontal stress all increase linearly with depth. (2) The intermediate regression value of (at 2 000 m depth) is various in study regions; and the basic characteristic of magnitude is high in east and weak in west. (3) The range of the lateral pressure coefficient Kav=225/D+0.61 with depth is: 15/D+0.42≤Kav≤1 030/D+0.76. The distribution of Kav is scattered in superficial crust, becomes more concentrated in the deeper crust and trends to 0.61. At a critical depth of 577 m Kav equals to 1 which indicates the transition from horizontal to vertical stress domination. (4) The predominant directions of are nearly E-W, NEE-SWW and NE-SW in east regions of North China. The directions of in study regions in and around Ordos block are mainly NE-SW and NEE-SWW. In study regions of North China Plain, the directions are dominantly shown as NE-SW; and NNW-SSE, and some directions are NW-SE. Fault stability in North China are investigated: The stress difference at depths bellow 500 m has not reached the critical value of fault activity; and stress difference at depth above 500 m has reached or exceeded the sliding friction threshold of the strike-slip fault.

The ancient Qiantang River seawall, built in Ming and Qing dynasties, is an important barrier in defending the estuary area of Qiantang River against floods and tides. To prevent strong hydrodynamic loads scouring the foundation and lowering the stability of the seawall, the apron structure is built at the front of the ancient seawall. The apron in the Haining region is mostly built by laying unbonded strip stones. To investigate the failure mechanism of such apron, wave and flow flume model tests are performed. It is shown that such apron is vulnerable to the impact by strong tidal bores where the covering stones are missing. The soil under the apron is vulnerable to the erosion by ebb tide seepage and longitudinal current, which leads to the sinking of the apron. As a cover layer, the apron has a good performance in protecting the soil, and can prevent the soil from instantaneous and residual liquefaction.

During working process, suction bucket foundation is not only subjected to the action of vertical load induced by the weights of fan and equipment, but also imposed by lateral loads caused by wind, wave, and current. In the case of high-latitude waters, the suction bucket foundation structures may also suffered by long-term ice pressure. To this end, by using three-dimensional finite element model, this paper researches on the horizontal ultimate bearing capacity and instability mode of suction bucket foundation under the saturated drainage sand conditions, analyzes the suction bucket foundation failure mechanism when horizontal loading slowly, discusses the bucket foundation bearing performance under different length-diameter ratios; and the earth pressure distribution and the rotation axis position of bucket inner and outer are studied. Furthermore, based on the limit equilibrium method, a formula of ultimate horizontal bearing capacity for the suction bucket under saturated drainage sand conditions is deduced. The study results can provide the reference and basis for the design of suction bucket foundation in sand ground.

In large-scale geomechanical model, because of the fragility and low strength of similar model material, it is difficult to get its complete bending stress-strain curve or load-displacement curve. This paper performed mechanical analysis on the bending experiment process, and got the stiffness designing principle of elastic element through some derivation for the solution of increasing the auxiliary elastic element.Based on this principle, we assembled a test prototype and obtained complete bending load-displacement curves for the specimens with different joints(homogeneous, layered and massive) containing different angles bolt. In addition, the dead weight of specimen was considered in the experiment due to the similar material's characteristics of low strength and bulk density. Experimental studies have shown that, the increasement of elastic element has a noteworthy improvement for the decreasing segment of the complete bending load-displacement curve. When the composite stiffness of the elastic element and prototype system is greater than the maximum stiffness of the specimen, the curve can be measured . The dead weight of specimen can be equivalent to the concentrated force in the bending experiment, and the equivalent load for the 550 mm long Standard specimen is 50% of its own weight or 9% of the peak load in homogeneous specimen’s experiment.

The stability assessment methods of surrounding rock roof under blasting load depend on the independent threshold safety criterion about the single intensity factor, which are mostly qualitative analysis without considering the three elements of the blasting vibration, so this kind of methods has some shortcomings and the insufficiency in engineering applications. The response signals are got through the numerical model of the different surrounding rock classes under blasting loads. The time-energy density function was used to analyze the time domain and frequency domain characteristics of the response signal; and the integral of the time-energy density served as eigenvalue was used to assess the blasting vibration effect. The quantitative relationship between the time-energy density integral(TEDI)and the roof damage degree of surrounding rock set the stage for improving the early warning system of rock roof damage based on the wavelet theory.

The main bridge of Yingwuzhou Yangtze River bridge is a three-towers and four-spans suspension bridge, for which north anchorage adopted circular caisson. A diaphragm wall was built surround the caisson before the caisson construction. According to the construction condition and the effect of caisson sinking to adjacent buildings, three dimensional calculation modes were established by MIDAS-GTS combined filed monitor data. It was mainly discussed the displacements agreement between calculation values and filed monitor data through some key points, and analyzed the effect of caisson sinking to diaphragm wall. It provided guidance to practice construction in order to predict the effect of follow conditions to adjacent buildings and the Yangtze River levee. The results show that: simulation results agree well with in-situ measurement; the errors are mostly among 5%-30%; and the adverse effects of construction can be effectively avoided to the adjacent buildings and levee; the deformation of diaphragm wall increases with the increase of sinking length; but the effect is more and more small. The calculation model will provide references in control of caisson sinking.

This paper gives the contrast studies on the mechanical models of the 3 piece of analytic formulae for elastic frozen wall of shaft sinking, and illustrate the two methods to solve mechanical interaction problem between frozen wall and surrounding rock with diagraph based on superposition principles. The basic law are revealed, that the load on frozen wall varies with their own thickness and rigidity. Upon the analysis of thickness difference calculated by the three formulas, the way of “heavy liquid formula” to evaluate the load on frozen wall of Lame formula is proved unreasonable. One proposal is put forward to evaluate initial stress field based on the principle of gravity fields and Terzaghi effective stress. The relationship between the original horizontal ground load and thickness of frozen wall illustrated by three formulas are shown with a practical example. The limitation of elastic design are studied with the mathematical principles of value region and domain，which are endowed with engineering meaning. The practical usage for the application condition of elastic design are further discussed deliberately.

Through in-situ investigation, the terrace model of Duba river is generalized. According to the geomorphic characteristics and hydrogeological investigation, Chenjiaba seismically induced landslide is located on the terrace the river; sliding surface is formed by long-term immersion of groundwater. Geological structures of sliding mass and the residua on terrace as well as the attitude of bedrock exposed at the front and posterior margin of the landslide are compared respectively; so failure mode of this landslide is determined; while the severe earthquake occurred, silty clay of the sliding surface are weakened by groundwater, which resulted in the sliding of unconsolidated accumulative formation on the terrace. The finite-difference and strength-reduction method is adopted to compute its stability factors under natural, rainstorm, seismic conditions. And three dimensional shapes of potential unstable body under different conditions are put forward.

Underwater blasting is a complicated, nonlinear, and dynamic process of energy release. It is affected by many factors, and its process has not been fully investigated at present. In order to accurately predict the peak particle velocity induced by underwater blasting based on a small amount of field measurements, the GRA-GA-BP model is established based on the grey relational analysis theory combining with the genetic neural network which has the nonlinear mapping and global searching capabilities. In the model, the potential information of the small sample is fully discovered, and the main factors affecting the vibration velocity are reasonably determined based on the grey relational analysis theory. Moreover, the problems of the neural network unable to automatically select and optimize input variables in complicated and multivariate systems are solved, which enhances the adaptability and stability of the genetic neural network. Finally, the GRA-GA-BP model is adopted to predict the peak particle velocity induced by underwater blasting at Dajin Island in the first phase of Taishan nuclear power station. Compared with the results obtained by traditional genetic neural network and the Sadaovsk formula, the prediction error of the GRA-GA-BP model is smaller and more stable. Therefore, the proposed procedure provides an appropriate way to predict the peak particle velocity induced by underwater blasting.

Combined with the project of mobile communication comprehensive building, Gansu Dingxi branch, China mobile in Dingxi new city, a lasting pile immersion test was made in the site of collapsible loess with large thickness; while the changing characteristics of pile negative friction and settlement process of soil were analyzed for different depths and limits (the diameter and length of test pile were 800 mm and 26 m respectively with 2 m pit in depth). The test results show that under the special immersion condition mentioned above, there appear multiple peak values along the pile, and positive and negative frictions presented staggered distribution phenomenon; so that the value of average negative friction couldn’t be given by Technical code for building pile foundation[1]; then with multimodal distribution of soil settlement amount, its changing tendency directly affects its trend in positive and negative friction along the pile; also, in the neutral point location, the single reference value provided by Technical code for building pile foundation wasn’t given; but several neutral points appeared along the pile; and the actual collapsible condition of loess is in sections, but not is sudden collapsible in the whole section above a certain neutral point as the traditional view states.

The testing and evaluation about the quality of dynamic compaction is a very important part during high embankment foundation improvement. Based on the theory and practice, the correlation of the test results between Rayleigh wave test(RWT), dynamic penetration test(DPT) and pile static load test(PLT) were studied according to the 1 000 kV ultra-high voltage(UHV) substation. Showing that the results of RWT and DPT can verify the results of PLT, and the first two can be used as indirect means for dynamic compaction detection, which may be appropriate to reduce the assignments of PLT which costs so much and lasts so longer. According to the test results, the mathematical expression of the test results are fitted. Based on the results, the relationship of Vs and fk can be expressed by power function, and the relationship between Vs and E0 and N120 can be expressed by exponential function. And the effective reinforcement depth of dynamic compaction and other soil mechanical parameters are inferred. Based on the measured value of the effective reinforcement depth of dynamic compaction, the correction coefficient from 0.24 to 0.27 were putted forward according to Menard formula. The research results will provide certain reference value for the similar projects.

As the natural barrier of the high-level radioactive waste(HLW) disposal project, the host rock is essential to ensure the stability and safety of the project in long-term. With the purpose to establish an effective method for evaluating the rock quality for site characterisation, the relation between the average structure spacing D, which is used as a quantitative index to describe the fracture distribution of rock mass, and the scores of relative metabolic rate(RMR) system is set up. It is shown that the point set, which is composed of the values of RMR and D, has a fan-shaped positive correlation. The value of D increases with the score of RMR. Moreover, the index of structure spacing D in lower order area shows a better corresponding relation with its rock mass quality than in higher order area. The method is used in the evaluation of rock mass quality around the borehole BS16 in Beishan area; and a good accordance between the distribution of D and RMR is obtained. The results suggest that it can be used as an effective and alternative approach of rock quality evaluation in the site characterization of HLW disposal project.

Aiming at the accumulation slope problem which is frequently encountered in the domestic southwest region hydropower project construction, the genetic mechanism and evolution process of accumulation slope was analyzed in detail on base of the piled rock mass characteristics, environmental conditions and engineering geology, and its formation. Generalized geological model has also been restored. Meanwhile, the research is also combined with the geological phenomena and drill core data gained from field displacement exploration. The results show that: the whole accumulation slope is a collapse accumulation, but in the process of formation, large-amount of local destruction occurred in district 1, resulting in geomorphology and internal structural differences between district 1 and district 2. At the same time, the macro-qualitative evaluation and detailed calculations of the stability analysis show that: the whole accumulation body tends to be stable, but the shallow overburden is quite, and in centre there are some local poor stability regions; in order to ensure the normal operation in later stage, and consider the engineering, environmental, and economic factors, foot presser was taken in district 1; cutting slope and retaining wall were taken in district 2. The calculation results can provide the necessary guidance and reasonable basis for the engineering design, and can also provide reference for the analysis of similar projects.

In seismic prone areas, it is necessary to study seismic stability of anchored rock slope. For anchored typical rock slope, the seismic safety factor of anchored rock slope against sliding and overturning failures is deduced by pseudo-static method and pseudo-dynamic method, respectively, in the different working conditions, considering both horizontal and vertical seismic forces, depth of water in tension crack, surcharge, dip angle of rock bolt, rock bolt position, tension force of rock bolt, and both hydrostatic and hydrodynamic pressures. The conclusions can be drawn that the upward vertical seismic force is conducive to the stability of anchored rock slope against sliding failure; but the downward vertical seismic force is conducive to the stability of anchored rock slope against overturning failure; in the same working conditions, the pseudo-dynamic and pseudo-static safety factors are all the same as the amplification factor is equal to 1.0; but the pseudo-dynamic safety factor is more and more obvious less than the pseudo-static safety factor as the amplification factor gradually increases. In seismic design, it will be beneficial to the safety design of anchored rock slope by appropriately considering the amplification factor.

As the construction of underground project grows increasingly, more and more tunnels will be constructed in gassy soil (soil layer containing high-pressure gas), and the gas in soil may bring bad influence for the stability of tunnel by shield method. When the shield machine is driving in the soil layer, the gas may enters into the tunnel through segment seam because of bad air-tightness, it will cause longitudinal deformation of segment. Aiming at this phenomenon, the purpose of this paper is to establish a segment deformation model under the condition that the gas enters into the tunnel through single point at the segment seam. For the purpose, firstly the stratum deformation caused by gas releasing was studied; the curve fitting method was used to obtain the relationship between stratum deformation curve and the maximum settlement value. Then the numerical simulation software FLAC3D was used to verify results gotten by theoretical deduction; Comparative results show that the numerical results and the theoretical results are basically consistent, so as to verify the availability of the theoretical formula. By segment deformation formula and deformation compatibility equation, the influence of different gas layer thicknesses and different initial gas pressures on the segment deformation and the open value of segment seam are analyzed; and the condition of soil layer causing the damages of segment is discussed. Results show that, with the increase of the thickness of gassy stratum or the original gas pressure, the bending moment of segments will increase; and the opening values of segment joints will become larger. For the stratum with thinner gas layer (<1.5 m) or lower gas pressure (<150 kPa), bad air-tightness will cause the gas leak and enter tunnel and bring the damage of segment; but normally will not destroy the waterproof facility of segment; however, for the stratum with large gas layer depth or higher gas pressure, that the gas leak will cause larger segment deformation and destroy the waterproof ability, and make underground water entering into the tunnel. When the deformation of segment becomes larger, the sand will flow into the tunnel with groundwater, so as to bring serious damage of segment.

During processing of section deformation’s convergent data of large underground cavern group engineering, obvious regularity is found at degree of fluctuation of the time history curve. Therefore, one-dimensional box dimension is introduced to quantitative description of this feature; and then relevant mechanical meaning of properties of surrounding rock is discussed based on the testing calculation results. Furthermore, the index is used to compare variation of the results of different monitoring cross-sections; and the corresponding relationship between integrity of rock and box dimension is confirmed. Through analyzing the relationship of various sections’ spatial locations and their box dimension values, the evolution tendency of rock’s integrity on the whole region is drawn. Finally, validity of the paper’s inference is proved by surrounding rock conditions which is revealed by subsequent excavation.

The ground vibration attenuation consists of geometric attenuation in the form of power function and damping attenuation in the form of exponential function. The Hyperbola-Logistic model is proposed based on the two characteristics. Through case study, it is revealed that the Hyperbola-Logistic model can not only be used to predict ground displacement and attenuation of velocity, acceleration, and vibration level, but also be used to predict ground vibration caused by train passing the viaduct section, embankment section and underground section. The Hyperbola-Logistic model has a better fitting precision, whose correlation coefficient R is above 0.95 and determination coefficient R2 is above 0.90, which demonstrates its credibility to predict ground vibration attenuation. This model shows its advantage both in quantitative value and distribution trends after comparison, so as to provide it a better way to predict ground vibration caused by the train.

In order to explore transfer bearing mechanism of thick composite roof in gob-side entry retaining, combining with characteristics that the composite roof is soft and proteiform and which leads to roof caving in gob-side backfill zone and roof cutting inside entry, systematic stiffness equation of roof, wall and floor is acquired through establishing mechanical model of supporting system beside entry, absorbing deformation characteristics are finally expounded. Roadway-side support system consists of direct roof, wall and direct floor, which bears the roof pressure integrally. The systematic stiffness is increasing with the rising of the stiffness of roof and floor; the rising effect is apparent when the original stiffness is low, in particular. The thick composite roof has a good performance on absorbing deformation, which is beneficial to relieving the pressure of roadway-side wall. For enhancing systematic stiffness of god-side support and strengthening transfer bearing ability of thick composite roof, the integral reinforcing technology is put forward. The research results have been applied to the condition of 10 meters composite roof successfully.

By the finite difference software package fast lagrangian analysis of continua(FLAC), a time-relied analysis is carried out to study failure process of heterogeneous serial and parallel rock pillars under cyclic dynamic loading. The theory of loading-unloading response ratio(LURR) is introduced to analyze dynamic stability of pillar. A LURR model of pillar is established by studying the laws of loading-unloading response ratio of pillar under dynamic loading. Through analyzing on the failure process of pillar, the loading-unloading parameter is determined as the periodical variation of dynamic loading. The displacement of pillar key point and elastic strain energy evolution regularities of failure elements are selected as loading-unloading response parameters respectively. Thereafter, the LURR time series of pillar is determined during the period of dynamic loading. It is found that the parameter Y of LURR can measure unstable degree of pillar. It can be applied to evaluate the stable state or predict the peak strength of pillar effectively. The results show that the loading-unloading response ratio theory is a very effective nonlinear dynamic analysis method in the dynamic stability prediction of underground pillar.

Gray clay of Zhanjiang Formation which widely distributes in Zhanjiang area have caused a series of geotechnical engineering problems in actual projects due to their strong structural characteristics which aroused great interest among Chinese scholars in 80 s of 20 century. It is difficult to understand the distribution of the Zhanjiang Formation, because different sedimentary environment shows different spatial distribution of the Zhanjiang formation in Leizhou peninsula. According to the data from site geology survey, 27 geological drillings had been done for the gray clay samples in different regions considering lots of factors such as topography, geological structure at Leizhou Peninsula as well as the sedimentary environment of Zhanjiang Formation. The typical profiles of different areas showed that gray clay had different sedimentary cycles, buried depth and thickness in different sedimentary environment. Its distribution is regional. The influences of gray clay on real projects were studied based on its buried depth and thickness. Additionally, a 3D geological model of spatial distribution of gray clay was established by using MAPGIS based on drilling survey data. This geological model can be used to study the spatial distribution of Zhanjiang Formation gray clays, and realized the visualization of gray clay spatial distribution. Finally, some basic applications of the proposed model are introduced.

Some strategies for developing mechanized production were put forward in view of the problems of great labour intensity and low production efficiencies of waste-lifting stoping method for gently inclined and extremely-thin veins. For adapting to the large-size stope structure of mechanized production, stability of stopes should be analyzed. Therefore, critical span of strope roof was calculated under the condition that caved debris was assumed to spring supporting part and stope roof was simplified as statically indeterminate cantilever beam structure with fixed-end of planar issue. At the same time, the calculation method applied in mine realizes the mechanical operation.

Lateral displacement control is an important factor for evaluating subgrade deformation during expressway construction period. This paper analyses the settlement deformation observation data of the soft ground distributed along the Suining-Ziyang expressway in Sichuan province, and researches the soft ground treated by PVD and gravel pile in Southwest China.Through observed data, we discuss the variation rules of subgrade lateral deformation(y) and depth(z), maximum lateral deformation increment(△ym) and surface settlement increment(△SD) and average lateral deformation(Sy) and surface settlement(Sf). The research shows that:（1）According to the Boussinesq’s formula and measured data, y-z curve is roughly S-shaped under embankment load area; y varies greatly near surface, but the maximum lateral displacement remains steady with load increasing; The depth of maximum lateral deformation does not related to embankment height but to soil property. (2) During filling period and precompression period, soft ground treated by PVD both produce large lateral deformations; the deformation of each period accounts for 50% of total displacement. The depth of maximum lateral displacement is 1.0-1.5 m from surface. (3) The lateral displacement of soft ground treated by gravel pile during filling period accounts for 75%-80% of total displacement which is much less than that treated by PVD; and the depth of maximum lateral displacement is 2.5-3.5 m from surface. (4) In consolidation stage, the value of △ym/△SD、Sy/Sf is 0.15-0.30 and 0.10-0.20 respectively of soft ground treated by PVD, 2-4 times greater than the early filling; while 0.10-0.15 and 0.03～0.05 respectively of soft ground treated by gravel pile. The variations of every stage are almost equivalent.

Currently, the calculation method of landslide-thrust and internal forces of anti-slide pile in essence belongs to the fixed value method. However, for the lack of considering geotechnical uncertainties, inadequate and excessive support problems for the anti-slide piles cannot be ignored. Thus, based on strength reduction of finite element method, the reliability analysis method of landslide-thrust and internal forces of anti-slide pile is proposed. In this method, the limit analysis, finite element analysis as well as reliability analysis are included. In the calculation process, 2-node beam element is used to simulate the stress condition of anti-slide pile; and the Latin hypercube sampling(LHS) method is used for reliability calculation; and above process is realized in the numerical calculation program. Landslide-thrust and internal forces of anti-slide pile are statistically analyzed; and function distributions can be achieved. With the control values of a given failure probability, the design values of landslide-thrust and internal forces can be accurately determined. Typical example analysis shows that the proposed method is significantly different from the general methods; it can reflect the slope present situation, overall characteristics and the variability of material parameters; and the results are closer to the reality.

The Verhulst biological growth model is a kind of statistical forecast model of landslide. According to the problem that there is no theoretical basis of taking the first displacement data as the known condition in the original Verhulst model; and a big error may be caused, the improved Verhulst model that other scholar proposed is firstly applied to the prediction and forecast of landslide. Based on the improved model and velocity maximum criterion, the calculation formula of displacement prediction and time forecast of landslide was deduced. Analysis of forecast results of different forecast criterions is another research content. Theoretical and case study indicates that taking maximum velocity as the forecast criterion of landslide time lacks rationality, and taking maximum of acceleration and accelerated acceleration as the forecast criterion is more in accordance with the mechanism of landslide. Then calculation formulas of forecast time based on the maximum criterion of acceleration and accelerated acceleration were deduced. Based on the deduced formulas above, the original and improved Verhulst model and the three kinds of criterion were applied to the time forecast of some actual landslides that had happened; and MATLAB software was used to calculate the time forecast. The forecast results indicate that, firstly, compared with the forecast results of the original Verhulst model, the forecast results of the improved Verhulst model are better, because the forecast time of improved model is closer to the actual occurrence time of landslide, and earlier than that of original Verhulst model. Secondly, as for the forecast results of three kinds of criterion, the forecast results of the acceleration and accelerated acceleration maximum criterion is better than that of the velocity maximum criterion, because the forecast time of acceleration and accelerated acceleration maximum criterion is closer to the actual occurrence time of landslide, and is earlier than the forecast time of velocity maximum criterion. Thirdly, it is suitable to substitute the single forecast time of the original Verhulst model with a forecast time range, and the upper limit of the rang is forecast time of the acceleration maximum criterion; and the lower limit is forecast time of the accelerated acceleration maximum criterion. Fourthly, the forecast time of the improved Verhulst model and the new time range criterion is more accurate than that of the original model, and it can play a role of early warning. In addition, the decrease of anti-slide force and increase of residual sliding force that is induced by increase of crack and decrease of friction coefficient is the reason why the acceleration of sliding mass increases gradually near failure.

Researching on the dynamic response of the rock slopes with weak layer has become an important issue in slope stability analysis. In order to discuss the influences of dynamic response of rock slope by weak layer’s characteristics and provide the directions and guidance for slope disaster prevention and mitigation under the dynamic load, the distinct element models are built and dynamic response of rock slopes with weak layer under seismic force are simulated by the universal distict element code(UDEC). After simulating in different conditions: various dip angles, burial depths, elastic moduli, thicknesses, Poisson's ratios and shear stiffness factors of the weak layer, the amplitude values of slope crest and bottom are obtained and the amplification coefficients are calculated; through systematically analyze the amplification coefficients, the amplification law of slope crest which influenced by seismic wave is got, namely, with increasing of dip angle, the amplification coefficient demonstrates increase→decrease→reincrease→decrease law, and appears response weakening phenomenon at the decreased parts. Along with burial depth and thickness increasing of weak layer, the amplification become bigger, but it decreases with elastic modulus and the shear stiffness increasing; the amplification almost doesn’t change with increasing of Poisson's ratio. Combining with the non-repetitive test binary analysis of variance evaluation theory, the obtained slope amplification coefficients are analyzed; and then, it is obtained that the significant factors which contribute to the slope dynamic response from great to small are the dip angle, burial depth, elastic modulus, shear stiffness, thickness, Poisson's ratio of the weak layer. The results are helpful to further researches on the slope instability mechanism under earthquake, and can provide the significante guidance to slope disaster prevention in earthquake region.

A main factor affecting the rationality of the sloped foundation stability analysis is to determine the position and shape of the sliding surface。Therefore the first problem of the sloped foundation stability analysis to be solved is to reasonably determining the position and shape of the sliding surface. The Mohr-Coulomb yield criterion, commonly used in the geotechnical engineering, shows that the failure of the rock and soil mass is due to the reach of the shear stress on someone surface to its shear strength, when there must occur a large shear deformation on the shear plane. Therefore, the sliding surface can be determined through searching the positions where have the largest shear strain increment. Based on the ideas above, comprehensively using the finite difference software-FALC3D and the curve fitting technique, the paper proposes a method, based on the largest shear strain increment, to determine the potential sliding surface. Its specific processes steps are that: firstly, the stress and strain in the slope are calculated by using the finite difference software-FALC3D; then a series of vertical line would be set in the calculating section, and then the discrete coordinates of the sliding surface, where the shear strain is largest on the vertical line, would be found through programming FISH program. Then the position and shape of the sliding surface can be obtained through carrying out the curve fitting of the discrete points by using the least squares method. The rationality of the proposed method is verified through comparatively analysing the limit equilibrium method. The method has a criterion with clear physical significance and is simple, convinient and practical for application and also overcomes the dependence of the calculting grid.

The stability of bank is very important for safety of bridge which is constructed on it. Therefore, the stability analysis of rock bank with masses of joints and faults under bridge load should be carried out for Furongjjang bridge. Based on the laboratory tests results, the machnical parameters of bed rock and cement face between skewback and bed rock are obtained. Considering effect of beding and vertical joints, the analysis of stability of bank is done with strength reduction method. And according to the calculation results, the slide surface is a typical polygonal line because of failure of joints and faults. After the construction of bridge, a practical slide surface would form under skewback due to huge bridge load; and it is very harmful to the stability of whole bank slope. Threrefore, it is necessary to reinforce the bed rock behind the skewback.

The major unstable mode of rigid anti-sliding pile structure is soil body at the side of anchoring section is pressed to lose stabilization. For calculating fuzzy random reliability index and reliability of rigid anti-sliding pile structure, at first, according to the extremum of pile-side-stress ?y below anti-sliding pile sliding surface in two depths, structural performance functions of anchoring depth reliability analysis of rigid anti-sliding pile is set up respectively. While calculating, the method of definite value is utilized to compare two extreme values at first. The structural performance function corresponding to greater extreme value is adopted to perform reliability analysis of anti-sliding pile. Then considering the randomness and fuzziness of structural reliability analysis of anti-sliding pile, fuzzy random reliability analysis model is set up. Based on first-order second-moment method (FOSM), the formula of calculating fuzzy random reliability is put forward. By using L-R type fuzzy numbers to describe the mean value and variance of random numbers, fuzzy numbers is disposed by decomposing theorem. Fuzzy reliability index and reliability of the structure are obtained. According to this method, a certain rigid anti-sliding pile is calculated by using MATLAB procedure. The fuzzy random reliability index and reliability of structure are obtained. The results of calculation and safety coefficient method have very good consistency.

In a numerical method for stability analysis of high rock slope, the analysis results will be influenced by the meticulous extent of description for rock mass structure. However, it is difficult to model meticulously for complex jointed rock mass in finite element method at present. In order to solve the problem, discontinuity network modeling and discrete element method(DEM) are combined used in this essay. Based on statistic data and classification of discontinuity, the meticulous description of complex rock mass structure is realized by network simulation program in UDEC. By means of constructing a fine geological model, strength reduction method based on DEM is presented and applied to the stability analysis of a high slope of a hydropower station. Compared the above results with LEM and general DEM, the numerical results show that the potential sliding surface and safety factor of slope are reasonable, with the usage of meticulous description of complex rock mass structure. Consequently, it will provide a new approach for analyzing the failure mode and stability of complex rock slopes.

Aiming at the Shanghai metro tunneling line No.4, that is, a tunnel within ultra-near distance crossed through the adjacent operating metro line No.11, the three-dimensional finite element method was applied to analyze the deformation distribution of the existing tunnel. The deformation analysis is based on three elements: different clearance distance, earth pressure of the chamber, injecting quantity of grout. Based on the results of the numerical modeling and theory of orthogonal analysis, the concept of influence coefficient for the overlapping tunnel is inferred. Through the results of orthogonal analysis, it was shown that: in the procession of overlapping, the distance affects the displacement field of the existing tunnel evidently; the influence on the earth pressure is secondary, injecting quantity effects slightly. These results could provide valuable preference to the technology of micro-perturbation control in the construction of overlapping tunnels.

Void ratio is one of the most important evaluation indicator of the silt compactness; the study shows that there are certain corresponding relations between liquefaction indexes and void ratio of saturated silt subgrade treated with vibroflotation; when the post-treated void ratio drops to bellow 0.75, the liquefaction of saturated silt subgrade could be eliminated. Based on the testing result and three-phase composition analysis of soil before and after the vibroflotation, the vibration effectiveness and compaction effectiveness of vibro replacement stone column are quantified; and the estimate method of post-treated void ratio is also derived. Compared with measured values, the estimate values calculated through the estimate method have errors within ± 1.5%. Meanwhile, the estimate method of post-treated void ratio are used to rapidly approach the optimal combination of pile spacing and pile diameter, so as to provide a reliable basis for saving the cost and speeding up the progress of pile testing.

In light of the squeezing deformation problem, based on Muzhailing tunnel research and other relative data analysis, it is concluded that large value and long time deformation are the squeezing deformation characteristics, both sides are usually advantage location in the whole deformation of tunnel. Test data show that surrounding rock pressure, stress of steel arch centering, axial force of anchor have a larger value in rigid support, where stress of steel may exceed the yield strength of material; anchor is more effective on side walls than other position; surrounding rock pressure and deformation increment is inversely proportional. The results show that rock pressure can be reduced by control release of surrounding rock deformation, is beneficial to the long-term stability of the tunnel structure. Yielding support is proposed, and reserved deformation can be predicted preliminarily. Numerical calculation shows that large enough stiffness is required for rigid support to control displacement in a small range, Yielding support has advantages in control deformation and reduces stress of steel; it is a better control technology in squeezing deformation tunnels.

The influence of structural property on foundation pit excavation is rarely considered. The foundation pit stability problem is widespread. The paper does the indoor triaxial test under the plain strain, and establishes the contact between the loess structural property and the strength, then introduces it into numerical simulation by FISH language; finally analyzes the influence of structural property on the stability of foundation pit. The study results show that the variation between structural parameter and strength indicators is consistant with previous findings. It is shown that the relationship between structural parameter and cohesive force is hyperbolic, but the parameters are slightly different. The influence of friction angle on the structural property is so small. Meanwhile, the paper finds the that significant slip zone appears in the pit sidewalls; and lateral displacement is greater than the continuous wall without considering its impact displacement; the foundation pit bottom uplift amount is also true. The results have a certain significance to design and construction of the loess foundation foundation pit engineering.

The simulation technique of materials’ failure has a great influence on the validity of the results. Based on the knowledge of materials’ failure criterion, two easily-overlooked issues in numerical simulation are put forward, which include elements’ erosion and inner contact after erosion during the numerical computation. With the background of cylindrical specimen’s failure test under compression loads and rock tunnel’s collapse test, the influence of the two issues on materials’ fracture are evaluated. Theoretical analysis and numerical computation indicate that, by defining constrained node set with failure and inner contact condition, the failure problem of materials and media can be properly simulated, such as the rock tunnel’s collapse, etc, the erosion algorithm for severe distorted elements has obvious imperfection.

It is assumed that a conceptual disposal repository for nuclear waste is located in a saturated jointed rock mass with certain water head, and a supporting system composed of rock bolts and shotcrete is installed after excavation of the drift. The construction of drift and a coupled thermo-hydro-mechanical(T-H-M) operation process of 50 years are simulated numerically by using UDEC code. The changes of stresses, displacements, plastic zones, temperatures, water flow in the rock mass of near field are analysed for cases with and without supporting; and the loading states of bolts and shotcrete are investigated under the conditions of coupling with different fields (temperature, water and stress). The results show: not only the rock bolts and shotcrete have the routine support function, but also are able to block free seepage of groundwater from the drift surface, so making plastic zone decrease, fracture pressure and temperature rise; compared with the case of action only by single stress field, the stability of surrounding rock mass is reduced, and the loading state of supporting structure is degenerated in the case of thermo-hydro-mechanical coupling.

In order to determine the stability of surrounding rock or the safety of concrete lining under blasting load, this paper adopted ANSYS/LS-DYNA software to analyze the dynamic response of rock mass under blasting vibration load when rock tunnel excavation with drilling and blasting methods . The results show that the attenuation law of blasting pressure，element effective stress and particle vibration velocity can be expressed by Sadaovsky empirical formula approximately, the attenuation law of particle vibration velocity and element effective stress have well relationship. Particle vibration velocity on the surface of surrounding rock is mainly along the axis of tunnel, and which is less along the normal line, and the least is on the surface. All particles on the same cross section have the same vibration wave shapes. The maximum particle vibration velocity on the arc is larger by 10% than on the wall slope, and that of conjunction is the least. The maximum particle vibration velocity of all nodes along the axis of tunnel attenuates according to Sadaovsky empirical formula. All the results are helpful to analyze the influence of blasting vibration field when excavating tunnel with drilling and blasting methods.

Building a patchy permafrost physical model, which is composed of multiple formations, the paper researches the effect of thermo-hydro-mechanical(T-H-M) coupling around the buried oil pipelines in Tahe on the base of considering the effect of environmental temperature and flow medium temperature in the pipelines, and analyses the stress of the buried pipelines and takes a strength calculation on the pipelines. The distribution of stress and sedigraph are acquired by the multiphysical fields coupling COMSOL Multiphysics software, which is used to simulate two kinds of working condition of T-H-M coupling and uncoupling. The numerical simulation results indicate that temperature, water phase transition and water migration influence the stress field greatly. What’s more, the coupling among the moisture field, the temperature field and the stress field is very remarkable. Because of temperature change, patchy permafrost takes on freezing or thawing, which results in stress concentration and settlement around the pipelines, so as to harm the safety of buried pipelines.

The excavation loads during blasting of deep tunnels are very complex; and it may have important influence on the development of excavation damage zone. Using PFC(particle flow code), the characteristics of surrounding rock damage zone induced by blasting load and in-situ stress transient unloading respectively under different in-situ stress conditions are discussed; and through the blasting excavation damage zone detection data of the Jinping П diversion tunnel, the results of numerical simulation are verified. Researches show that the degree and range of surrounding rock damage zone induced by blasting load or in-situ stress transient unloading will increase significantly with the increase of in-situ stress degree; the damage zone will mainly appear in the area of stress concentration as the lateral pressure coefficient increased under the conditions of blasting load, the surrounding rock failure induced by in-situ stress transient unloading is mainly composed of tensile failure, the surface damage zone will uniformly distribute on excavation face; the depth of surrounding rock damage zone induced by blasting load and in-situ stress transient unload respectively under the same in-situ stress are all significantly less than the measured values, which in agreement with the measured values when considering the coupling effect of the two load. It is shown that this two kinds of loads are the main components of blasting excavation load under high stress conditions; but the surrounding rock damage zone induced loads by the coupling action of this two kinds of loads is bigger than the linear superposition of their separate effects.

Based on the transversely isotropic elastic constitutive model in the local coordinate system of bedding plane, according to the occurrence of layer, the stress conversion method from the global to local coordinate system is derived. For the anisotropic characteristics of the layered rock mass, the failure mode is subdivided into five kinds, for which the discrimination function, yield criterion and corresponding stress modified iteration calculation are respectively established according to plastic flow rule. A second development is carried out with VC++ programming language to generate a dynamic link library DLL file called by FLAC3D main program at any time. The strength and deformation properties of layered rock mass are studied through uniaxial and triaxial compression numerical experiments which indicate that the inclination angle and the confining pressure have an important influence on mechanical behaviors of layered rock mass. Compared with transversely isotropic elastic model as well as ubiquitous-joint model in FLAC3D, the correctness and accuracy of the new model are verified. Finally, the new model is applied to the calculation of an ideal circular tunnel in triaxial equal pressure in which the variation rule of failure modes of the layered rock mass influenced by the azimuth is analyzed. The results indicate that the altitude of bedding planes of layered rock mass is playing a control role to deformation distribution, failure mode and the propagation direction of plastic zones.

Based on damage mechanics theory, a mechanical model for rock blasting is established considering of the rock heterogeneity, in which rock blasting is considered as two consecutive stages, i.e. the dynamic stage caused by the stress wave and the static stage caused by explosion gas pressure. The cracks evolution of two-hole blasting under different in-situ stress conditions is numerically simulated. The numerical results indicate that: ① the initiation of cracks is induced by the blasting stress wave, while the explosion gas pressure can lead to the further propagation of cracks; ② the cracks evolution is closely related to the in-situ stress conditions, and the cracks propagation direction coincides with the maximum compressive principal stress; ③ the cracks radius and cracks area decrease with the increasing of depth and in-situ stress, which implies the suppression of in-situ stress on blasting fracturing.

Firstly, it is analyzed bond mechanism between anchor and soil in anchor slope under dynamic loads; then a simplified dynamic model of interaction between anchor and soil is proposed; and a dynamic responses analytical solution to anchor and soil system is deduced. According to this simplified dynamic model of anchor and soil, a numerical model of anchor slope is established by ANSYS program. And the effects of anchor parameters, such as elasticity modulus, cross-section area, length, space on seismic performances, such as displacement, acceleration, stress of anchor slope under the effect of seismic load are analyzed. Analysis results indicate that the anchor parameters have different effects on seismic performance of anchor slope. Increasing anchor cross section area is able to improve seismic stability of slope effectively; and decreasing anchor space is also beneficial for improving seismic performance of anchor slope; while changing elasticity modulus and cross section area have little effect on enhancing seismic performance of slope, instead increasing elasticity will play negative role for improving seismic performance of anchor slope. These conclusions may provide some references for anchor slope seismic design.

Coal bumps have been a major safety concern in underground coal mines in China for more than fifty years. In general, a coal bump refers to a sudden and violent failure of a coal seam that releases contained elastic energy and expels a large amount of coal and rock into the roadway or working face where men and machinery are present. It can cause fatality, injury and significant economic loss for the coal mining industry. Coal bumps occur more frequently in an island longwall panel, which is surrounded by previously mined panels, than in other longwall panels because of its high-stress concentration. In order to investigate the suddenly release of strain energy during extraction of mining face, the nonhomogeneity of materials will be considered to understand the mechanism of energy explosion during periodic weighting of the island longwall panel. Numerical simulations were conducted to study the dynamical character of elastic strain energy relief based on the geological conditions of T2193B island longwall panel in the Tangshan coal mine. Numerical results suggest that the constant collapse of immediate roof will cause continuously increasing of the main roof suspension. Meanwhile, the accumulated elastic strain energy in main roof will abruptly release when the periodic weighting occurs. At this moment, the coal bumps will occur more frequently in the mining face and roadways. It can be revealed that elastic strain energy explosion of main roof and coal seam during periodic weighting is considered to be an important precursor of coal bump occurrence during the extraction of an island longwall panel. Therefore, the significant reason of occurrence of coal bump is the suddenly elastic strain energy explosion during the periodic weighting of man roof. This study of coal bumps in the island longwall panel is of significant importance for coal mine safety and productivity.

Rolling resistance is a force couple transferred between two contact particles, which is used for resistance particle mutual rotation. It is an important modification to introduce rolling resistance into discrete element method. In this paper a contact model considering rolling resistance is developed and installed into PFC2D. Using this model, a series numerical model of biaxial shear tests of course-grained soil are carried out to investigate the effects of rolling resistance on the macro- and meso- mechanical responses of particle assemble. The results show that: (1) In macro scope, the shear strength and volumetric response are increased with rolling resistance which is consistent with former researches, and this confirms the validation of the model used in this paper. (2) In meso-scope, the effects of rolling resistance on microstructure of coarse grained soils are investigated; the results show that contact numbers decrease with increasing of rolling resistance; while the shear strength are just to the contrary, that means rolling resistance enhances the stability of force chain network of coarse grained soils. The results show that the contribution of increasing anisotropy with increasing rolling resistance belongs to strong force chain. That confirms that rolling resistance improves the force transmitting ability and resistance of force chain buckling failure of strong force chain. And non-coaxial phenomenon is also observed in this study.

Prefabricated vertical drains (PVD) incorporating with a heat source, which can accelerate the foundation consolidation in vertical drains system, is stimulated by finite element method based on the thermo-hydro-mechanical (THM) coupling. Firstly, both differential form and weak form of control equations for THM coupling problems are presented; and the finite element formulations are deduced. Secondly, a fully coupling THM model is established in Comsol Multiphysics software. Comparison between numerical results and analytic solutions are carried out in order to validate the model. At last, a representative calculation example of a single drain foundation in which has a smear zone is adopted. In order to study the influence of the thermal effect on consolidation, the example is modified through a heat source set in the well zone; and three cases (1) uncoupling temperature(UT), (2) coupling temperature without considering the thermal effect on property of soil (CT) and (3) coupling temperature with considering the thermal effect on property of soil(CTP) are executed. The results show that the rate of consolidation decreases a little in the CT case since the heat source produces the extra pore pressure; and increases significantly in CPT case due to the higher temperature enhancing the hydraulic conductivity in smear zone.

Several methods are available for account the soil aching effect in the pile-supported embankment; but these present methods produce dramatically different results partially due to the different analysis models. To avoid the macro continuity hypothesis of traditional continuum mechanics model, a two-dimensional numerical model using particle flow code(PFC) has been established to simulate soil arching effect of pile-supported embankment. One part of the numerical analysis deals with load transfer mechanisms by investigating the contact stress, stress distribution and vertical displacement. Also the simulated results have been compared with model test results. The other part of numerical analysis consists to a parametrical study investigating the influence of the size of the pile cap, pile spacing, the fill height, particle size and the friction angle of embankment. It is shown that: (1) The local soil on the top of pile can be regarded as elastic nucleus. Soil arch forms were affected by forms of the pile cap, clear spacing of pile cap and geogrid. (2) The soil aching area is located around one time pile cap clear spacing over the bottom of embankment. (3) The vertical stress and lateral stress in the inner arching vary with depth nonlinearly and pile -soil stress ratio increases with the load level , the friction angle and particle size of soil.

Based on the engineering background of Shirengou iron mine, the evolution law of stress and strain of wall rock during formation process of goaf group in a typical ore blocks using similar material physical models and numerical simulation was researched. Firstly systematic analysis was made on evolution law of roof’s stresses and displacements and pillar’s stresses through the similarity material test. Secondly the disturbance range of wall-rock in the formation process of goaf group was systematically studyed using numerical simulation software. The results indicate that the evolution law of stresses and strains are great difference among goaf group and single exploitation. During the formation process, the stresses and strains of wall-rock are in dynamic development especially in the middle region of goaf group where the state of stresses and strains are worst. The disturbance to the wall-rock caused by mining in group region increases rapidly and the final disturbance range is not simple addition of which caused by mining single goaf. It is indicated that there is some “group effect” in the region that enhances the hazard grade of goaf.

Feasibility research of high bench blasting belongs to multiple factors and complex system project. In view of the feasibility research status of high bench blasting, a method of feasibility of high bench blasting considering blasting mechanism is put forward. Through comparing with difficult burst positions ( bench top and bottom ) stress field variation trend of the existing ordinary bench and high bench blasting process, it is found that the use of high bench blasting can obtain the existing bench blasting equivalent or better blasting results. From the blasting mechanism analysis, it is shown that the high bench blasting technology in the Barun ore is feasible. The numerical analysis results show that the best detonation mode of high bench blasting is all grain simultaneous blasting; the better ones are intermediate and ends of the detonation initiation; the unsuitable way is the hole bottom detonation.

For the models of stress corrosion and pressure solution used in the 2D finite element method(FEM) code of thermo-hydro-mechanical coupling analysis for dual-porosity medium developed by the authors, a correction factor for water saturation is introduced. Aiming at a hypothetical model for geological disposal of nuclear waste located at a water-bearing stratum, three computation conditions with different initial fracture saturations were designed(Sw20=1.0、0.8、0.2), then the corresponding two-dimensional numerical simulation for the coupled thermo-hydro-mechanical processes were carried out; and the states of temperatures, rates and magnitudes of aperture closure, pore and fracture pressures, flow velocities and stresses in the rock mass were investigated. The results show：With the change of initial fracture saturation from high value to low value, the closure rates caused by stress corrosion and pressure solution vary from fast to slow, and the times of fracture aperture tending to its residual value and contact-area ratio of asperity tending to its nominal area from their initial values also increase, as well as the drop in stress intensity factors slows down; the changes and distributions of fracture and pore pressures in near-field as well as the states of flow vectors have obvious distinctions; the magnitudes and distributions of stresses within the rock mass in three calculation cases make little difference.

The plane strain analysis method was widely adopted in evaluation of dump slope stability. It is embarrassed that, dumps sometimes destroyed but the safety factor was go over the allowable value. Regardless of those issues had been mentioned frequently, such as mechanical parameters, constitutive model and so on, the spatial clamp effect of convex and divergent effect of concave and slide-body-end effect are also play vital roles in analysis of slope stability. For those reasons, proceed from conditions of plane elevation data, geological section, drilling data and others, Kriging interpolation method, which can obtained a smooth effect of interpolation, was adopted, and then the three-dimensional(3D) geological model of dump was built. Then an interface program, wrote by FISH, was used to import the 3D-model into FLAC3D to discretization and calculation. In this way, the issues mentioned above can be figure out efficiently. Trinity function include 3D geological modeling, model visualization, geotechnical analysis was achieved in a simple and highly efficient way. An example of Jianshan seventh dump of Lanjian Iron Mine, Pangang Group co. Ltd. of China, was concerned by previous mean, 3D stress-strain analysis was carried out, 3D global safety factor was also calculated by 3D strength reduction method. It turned out that the results was accordant to the field investigation and plane strain analysis conclusion. Results calculated by the 3D geological model cannot be affected by dump spatial effect and slide-body-end effect, the general stress-strain pattern, which obtained from the method, can be instructive and meaningful to production management for open-mine dumps.