A settlement of surface is an environmental hazard. A new model was proposed to forecast exactly the change law of a settlement during the complete process of construction and operation. Either Poisson curve model or Verhulst model is a special case of the new model. A new concept and method are proposed to break through limitations of a three-piece algorithm used by Poisson curve model. It combines a nonlinear regression method and a cubic spline interpolation method. Solutions to the new model are obtained by the new method. An example is given and discussed. Results show that the new concept and method can give precise solutions of the model and that the resolve between calculated results from the new model and measured ones is reduced greatly compared with that from Verhulst model. The new model can provide geotechnical engineering design with new scientific basis.

Based on the consolidated finite layer theory, the analysis method of the nonlinear interaction on pile group-soil-raft considering soil consolidation is built in the study. And the corresponding computing program CPRI, which simulates the whole consolidation procedure by the nonlinear interaction and provides the variation of the displacement, pore pressure, resultant force of pile head and the soil counterforce at different time, is developed. At the same time, the flow chart of main program and pile-soil-raft system subroutine are presented. Through the test of the computing example compared with the program PRI, the correctness of the program is proved.

Rock mass quality classification is an interesting and formidable issue in the study of rock mechanics, and it plays a very important role in the hydropower engineering construction. With the study of many classification methods, the engineers desire higher regalements for the expression of rock classification. Traditional ways cannot meet the demand of spatial analysis already, and the visualization of rock mass quality classification will be very necessary. Firstly, with a new data structure, 3-D strata model is reconstructed using NURBS tool. Then, according to the classification results, the corresponding 3-D classification model can be generated by set operation algorithms of space pattern. The theory is applied to rock mass quality evaluation of Jinping first-level hydropower engineering successfully, and a series of visual analyses correlating with engineering design are also operated. This study acquires very good effects in the practical application.

Based on in site test of soft clay foundation treated with dynamic consolidation by drainage and dynamic consolidation tests in lab, the dynamic characteristics of strain and pore water pressure of soft clays under impact loading were analyzed associated with soil pressures. The study has shown that the axial strain and pore water pressures with impact number have different development models. The relationship between axial strain and impact number is of hyperbolic-logarithm function, and the development model between pore water pressure and impact number is of hyperbolic function.

Roof mechanical characteristic before and after disposing abandoned stope is studied respectively by rock mass stress, displacement and seepage computation, together with their coupling analysis （EPSCA3D） and 3-D FEM (ANSYS) in Mujia Hill and Dongtongyu Gold Mine. The results show that after disposing abandoned stope, surface subsidence and rock movement will decrease due to seepage. The stress change on roof lies on rock-mass permeability and seepage direction. The influence on stress redistribution resulting from penetrability is greater than that from the seepage direction. If the seepage direction is almost horizontal, the tensile stress increases, and the press stress decreases on roof of upper part of abandoned stope. If the seepage direction is nearly 1350, the tensile stress and the press stress both decrease in roof of upper part of abandoned stope. The rock-mass permeability and seepage direction are controlled by existing water-resisting layer.

Research results and engineering examples are concluded on the characters of overburden strata movement of mines. Based on it, some proposals are presented on safe mining depths.

Based on the mechanism of earthquake-induced differential settlements of buildings, an analytical method of the two-dimensional FEM for estimating the earthquake-induced differential settlement of buildings is presented. Using the model of residual strain of soils under irregular loading and progressively softening model, the method can consider the combined action of the soil, structure and seismic wave more reasonably and can describe the process of the differential settlements of the buildings. The comparison results with large shaking table tests indicate that the new method is reliable.

The probability distribution type of soil strength affects the results of reliability and risk analysis of geotechnical problems. Many soil and rockfill samples have been collected from earth dams and tested in lab. The probability distributions of these soil or rockfill samples are coincident with the theoretical normal distribution or logarithmic normal distribution. The selection of logarithmic normal distribution in risk and reliability analysis can avoid the parameters to become negative, so it is more acceptable.

In the light of a failure project, the stability calculation methods for large cylinder structures in coastal soft clay foundation are compared, and the determination of design values of soft clay in the wave action and effects of foundation scour on the stability of large cylinder structures are discussed. It is shown that the stability calculation methods of the traditional gravity structures are unsuitable for (can not be used in) the stability analysis of the large cylinder structures in soft soil foundation. It is proposed that the dynamic behavior of soft clay in the action of circle load, the evolution of foundation in fluid scouring and dynamic interaction simulation of large cylinder structures and soft clay under the wave excitation should be the key problems to be solved in the practical application of large cylinder structures in coastal soft clay foundation.

The article is aimed at the computation of seepage field in fractured rocks of hydraulic projects, presents a 3-D finite element analyzing program according to the method of Double-medium Solution, in which the main fracture network and the fracture rocks are coupled by interchanged water. In the program, the position of the free face is found by imaginary point method and reasonable results are obained. The seepage model for computation is set up and divided grids directly by the software of ANSYS, the corresponding pre-disposal program greatly simplifies the computation and increases the practicability of the theoretic methods.

Five blasting tests are carried out in Niutoushan hydraulic engineering project, Fujian province, east China. The vibration velocity of jointed rock mass under explosion is simulated by the discrete element program UDEC. And the attenuation characteristics of the peak particle velocity and particle oscillation frequency are obtained. In succession the inputting explosion loads of the numerical model are modified according to the charge weight alterations in each blasting test. Thus the relationship between the peak particle velocity and the charge weight is acquirable when the distance between the monitoring point and the charge hole keeps constant. Also the variation of the particle vibration frequency with charge weight is known in the same way. It is observed that numerical modeling results, on the whole, agree well with those of the field tests. For this case, UDEC is applicable to simulate the dynamic response of jointed rock mass subject to explosion.

Based on mesoscopic damage mechanics, numerical code RFPA2D is developed to simulate the failure process of seven transversely isotropic rock samples under uniaxial loading. The rock samples are composed of two different rock materials and they are formed with different dip angles between the rock layer orientation and the loading direction. Complete stress-strain curves are obtained and the deformation and failure behavior are described. As shown as the numerical results, rock layer dip angle of transversely isotropic rocks has much great influence on the failure process, such as peak strength, failure modes, and deformation characteristics et al. It is suitable to apply different failure criteria according to different failure modes caused by layer dip angle. The results of another serial of numerical simulations is well agreement with the experimental studies. The difference between the numerical simulations and experiments is probably caused by plane strain problems and parameters used in the simulations.

Two transfer coefficient methods, based on over-loading method and strength reserve method, which are commonly applied to evaluate rock landslide stability, are validated at present through analyzing the results between limit equilibrium and finite element method. In this paper, the reliability of the two methods is validated through rock similar material modeling test on the background of Zhaoshuling landslide of Badong in the Three Gorges Reservoir area. Research result shows that the stability factor values calculated with these two methods are lower than that from modeling tests, and the value from over-loading method is preferable, of which the assumption of the essistence of tensile strength between blocks accords with the failure character of the model is given. However, the stability coefficient on the basis of the strength reserve method is far from that from testing. The transfer coefficient method based on the over-loading method is realialde when used in practical engineering.

Matric suction is a very important concept in unsaturated soil mechanics, and it is not easy to understand its physics significance. The concept of matric suction and some questions on matric suction are discussed in this paper in term of basic formulae of surface physical chemistry, i.e. Young-Laplace formula and Kelvin formula. The rebuts indicate that the magnitude of matric suction in soils is controlled by aperture size, and it is interrelated with equilibrium retative humidity of the circumstances, and distribution curve of pore size determines the characteristics of the moisture retention curve.

From the viewpoint of system theory, the concept of large complex system of landslide hazards is put forward, based on which the characteristics and fundamental contents about the risk analysis for landslide hazards is studied The hazard analysis of landslides and the vulnerability analysis of landslide hazards affected body as well as the loss evaluation of landslide hazards taken as the key contents are systematically described.

As rigid pile composite ground is getting more and more applications in construction engineering, the research on its anti-seismic behavior becomes very urgent. This paper is concerned with the seismic analysis of type of composite ground. A model is proposed, based on the Beam on Dynamic Winkler Foundation theory, for the analysis of a single pile composite ground. The partial differential equations for its seismic response are derived and the finite difference method is applied to obtain the numerical solutions. Comparative studies are carried out to investigate the effects of various influence factors on the earthquake response of this type of composite ground. Valuable findings are obtained which can be of importance for its design.

The construction of embankment of highway can be regarded as a linear loading process, during which the soils are filled gradually on the ground. Based on the stress-strain relationship of the soil mass, the characteristics of settlement~time curve (s-t) of the ground under instant loading, linear or approximately linear loading are analyzed respectively. The results show that the s-t curve is inversely S-shaped. According to the behavior of s-t curve, the Gompertz model is established to predict the ground settlement. The three parameters in the model, a, b and c can be easily solved by SAS program. This model is used to study 4 cases. The comparisons illustrate that the settlement predicted by Gompertz model keeps good agreement with the measured data.

One of the key problems must be solved during the construction of the Ninghuai Expressway is how to use the modified expansive soils to construct the embankment. There are three main problems that should be solved for the proper use of the modified expansive soils: the first is how to mix lime into soil homogenously and how to detect lime contents; the second is how to compact the lime-modified soils effectively and what is the proper optimum Proctor density; the last is whether the characteristics of the filling of lime- modified soils is with satisfied the design requirement. Field tests have been conducted to require these questions. The results of the field tests show that the lime-modified soil has low swelling rate, low compression, and high strength if there is reasonable construction method and suitable quality controlled system.

The texture of mineral particle is the key point to the mechanical property of rocks. Two kinds of marbles are uniaxial and triaxial compressed. One is slightly weathered with fine-crystal in size of 0.5mm～1mm, the other is weathered with silt-crystal in size of 0.2mm～0.5mm. The silt-crystal marble has much internal boundary to slip during compressing, so the Young’s modulus willbe changed greatly with the cohesion, and the dispersion of Young’s modulus is greater than that of strength. On the other hand, the fine-particle marble is 3 times in Young’s modulus but only 20% in uniaxial strength more than the silt-particle marble. In pseudo-triaxial compression, the Young’s modulus increases with confining pressure for silt-crystal marble, but it is nearly the same as fine-crystal marble. The triaxial strengths of the two marbles in ductile deformation are closed each other. The angle of shear failure increases with the confining pressure and finally reaches the value from Coulomb criterion The supporting capacity of marble specimen is only related to the confining pressure and no matter with the loading path, material strength and flaws. The internal friction between crystals determines the strength and deformation of marble.

This paper simulates the stress paths in unloading state during excavation effect of lateral unloading on shear strength of soil mass is studied, and the reasons are analyzed according to the microstructure of soil samples. The test results show that the shear strength of soils after lateral unloading are different from that of conventional triaxial test.

Studies have indicated that the shear strength of soils is influenced by the intermediate principle stress. Generally, the shear strength of soils is correspondent with Mohr-Coulomb criterion under the condition of compression and extension in triaxial tests; but in the condition of three-dimensional stresses, soils have a higher shear strength, and the failure points on π-plane are beyond Mohr-Coulomb criterion. Based on true triaxial tests, this paper proposes an angle of equivalent internal friction and a failure criterion for cohesionless soils. The criterion can take into account the influence of intermediate principle stress. Compared with the results of true triaxial tests, it is found that this failure criterion is better than Mohr-Coulomb criterion. It is promising that the failure criterion can be applied to the cohesive soils in the future.

The finite element expressions of two-dimensional seepage equations are obtained. The Darcian velocities after the suspended curtain construction are compared with that before it as well as the hydraulic gradients on the location where water comes out in the downriver. The results have showed that they decreased notably except that the velocities increased in small curtain bottom areas. The anti-scour performance should be improved on the curtain bottom when it is used in the hydraulic projects.

The results from the consolidated undrained triaxial compression tests and the consolidated drained triaxial compression tests on the refuses with various compositions, have shown that the constitutive relation of the tested refuse basically fits the Duncan-Chang nonlinear elastic model. The organic and soil contents of refuses are the important factors that affect the strength parameters of refuses. For the refuse with higher organic and lower soil contents, the lower value of cohesion c and higher value of internal friction angleφshould be adopted .The values of c,φ and their variation are given. The values of c will increase and the values ofφ will decrease with the variation of time. Although the value of axial strain of refuse exceeds 30 %, the phenomenon of the increase of the principal stress difference is observed. The hysteresis pore water pressures in refuse during the consolidation are analyzed. The variation of the seepage coefficients k is related to the stress, time and the composition of the refuse. The pore water pressures of the refuses will increase with the increase of axial stress during the shear of the consolidation drained triaxial compression tests. The total stress strength parameters are not the effective stress strength parameters.

The principle of time-temperature superposition (TTS) which can accelerate creep test of geosynthetics is introduced. The calculated formula and method of time shift factors are also introduced. If an inflexion point is present in curves, adjacent curves are shifted both horizontally and vertically. The creep strength of geosynthetics at the designed life by TTS can be determined by the curves of stress vs time. The creep reduction factor is determined with dividing the ultimate tensile strength by long-term creep strength. The procedures of determination of creep strength and creep reduction factor by TTS are mainly discussed in this paper. Finally, an example and some suggestions about improvement of this method are given.

In order to obtain the rule of creep failure of high ground stress rock, the process of creep failure of surrounding rocks is simulated under the action of high ground stress at different depths in deep engineering, then time-creep, horizontal ground stress (depth)-creep curves and time-horizontal ground stress (depth)-creep curved surface are obtained. According to the rules of Mohr-Coulomb and Griffith, the theory of nonlinear creep is proved. And a new idea is offered, which predicts the deformation of tunnel wall rocks surrounding in deep engineering The non-linear rheology theory proposed by Zheng Rongming and Sun Jun is verified through calculotions.

This present paper deals with the interaction analysis method of pile foundation established on thick and soft groundsill. A contact interaction model is given to simulate the interaction between pile and soil, soil and base slab. As for the superstructure, it uses substructural method to take its stiffness into account to the settlement of foundation. It regards the soil as elasto-plasticity, and uses infinite element to account for the effect of far field groundsill. In the end, an analysis example is given. From the results, It can bee seen that the analysis method adopted in this paper works very well.

The contact element model is introduced to simulate the pile-soil’ s reciprocity,then the paper derived the contact element stiffness matrices by adopting parameter variable’s variational principle and parameter variable’s second programming method.With comparison of computing result and test in situation ,it shows that the contact element model is suited to simulating the pile-soil’ s shear force transmission and relative displacement.

A brief description is given to the currente status of the study on slope rochmass deformability and FLAC-3D soft mare firstly and then, using FLAC-3D,deformation of Gapa landslide is studied by means of numerical simulation under natural situation and impounding conditions. On the basis of calculation results obtained from simulation, by means of analysis of displacement value of character ristic points in the main section and displacement vector, deformation features under natural situation and different impounding conditions are given . The relation of deformation features and stability of landslide is established . Finally, essential theory is given to evaluate stability of Gapa landslide in the future.

In consideration of difference in micro-structure of rocks, the paper presents random non-homogeneous solid-head coupled model and FEM concerned, and then in consideration of the random non-homogernity of thermal dilation and conduction coefficients, plane stain model, For example of granite, assumed thermal dilatability and thermal conduction with uniform distributing, Gauss distributing, Weibull distributing, based on a lot of numerical experiments, study on the hot cracking threshold of rock, conclusions of random distributing function and parameter and time influence to thermal cracking law and temperature threshold is presented.

The Mechanical pre-cutting method used in soft ground is a kind of preparative support, it allows tunnel excavation work to be conducted efficiently under the safe pre-lining. In this paper, a 3D FEM program based on tunnel mechanics and elastic-plastic theory is developed to analyze the ground deformation when excavating tunnel by Mechanical pre-cutting method and the conventional full section method. The result show: the Mechanical pre-cutting method has evident advantage in controlling ground deformation compare to the conventional full face method because of its preparative support function. The pre-cutting method can reduce the ground deformation range and extent in tunnel construction, so it can be used in tunnel construction in the district where the strict limitations on surface settlement is set.

In order to investigate the rheological properties of Lianyungang soft marine clay, a triaxial rheological test is performed. Based on the analysis of laboratory tests, Lianyungang soft marine clay can be regarded as an elastic-viscoplasticity. Then, the generalized Bingham model and the ellipse-parabola two-yield-surface model are combined to develop a new rheological model to describe its rheological behavior. Finally, all the parameters are obtained and the applicability of this model is validated.

The problem of solving the seepage field with complicated boundaries frequently involves rainfall infiltration boundary as well as densely-distributed drainage hole boundary. This is in general an unsaturated seepage problem, and therefore, the traditional steady saturated drainage substructure model is not applicable any more. In this paper, according to the two classified drainage holes, typical subdividing modes for the two types of drainage holes are offered and a hydraulic model for unsaturated drainage substructure is presented correspondingly. Additionally, other boundaries like rainfall infiltration boundary which are not considered in traditional model are introduced, making the model more comprehensive and improved.

One-dimensional consolidation of soft clays under cyclic loadings taking into account the impeded boundaries is studied in this paper. According to the solution in the condition of constant loading, the analytical solution under cyclic loading is obtained using the integral. method Based on the analytical solutions, the influence of loading and boundary conditions on the consolidation behavior of soils is investigated and It can be seen that a decrement in permeability of sand mat and subjacent bed will reduce the rate of consolidation significantly and that the consolidation rate and the pore water pressure reach the maximum and the minimum once in each cycle for cyclic loading.

In this paper the principle of the Genetic Algorithm is stated. There are some thorny issues such as the limitation of the primary search ability when the Genetic Algorithm is applied to blasting vibration in parameter inversion. The Compositely Genetic Algorithm is provided to solve this problem. Numerical example shows that the Compositely Genetic Algorithm is efficient and reliable.

The analytical method is adopted in classical geotechnical engineering limit analysis method. It cannot involve the stress-strain behavior of soil and sometimes assumptions needs to be made in advance about the shade or location of the failure surface. It is not suitable for heterogeneous materials, especially the rock engineering. So its application still remains limited. With the development of computer and computing technology, the limit analysis finite element method was put forward. With the strength reduction or load increase, the stability safety factor and failure surface can be obtained directly at limit state. It is very practical for geotechnical engineering design. This paper studies the limit analysis finite element method and its application in the slope、tunnel、ultimate bearing capacity of foundations. Through a series of case studies, the applicability of the proposed method is clearly exhibited.