A nonlinear elasto-perfect plastic model of interface element is presented. The proposed model can simulate behavior of soil and structure interaction. The stress-strain relationship and nonlinear elasto-perfect plastic matrix of interface element are established based on elastoplasticity theory. The computational procedure for implementing this-type of nonlinear and inelastic interface element in the finite element methods is developed and numerical scheme is presented. Then the method is applied to numerical analyses of foundation pit excavation. Through numerical computations for an example of the foundation pit excavation and bracing, the distributions of earth pressures behind and in the front of pile wall along the depth and their variations during the excavation of foundation pit are examined. It is indicated that the proposed model can rationally simulate the stress-strain relationship of interface element and will be practically applicable.

Displacement predication of landslide is very important in control of landslide disaster. Considering the monotonously increasing character of the displacement time series of the landslide, a new intelligent prediction method combining grey system and evolutionary neural network (ENN) is proposed. In this method, based on the principles of displacement decomposition, the trend of displacement time series is extracted by grey system and the deviation of grey system is approximated by the ENN whose architecture and algorithm parameters evolve simultaneously through combining modified BP algorithm and immunized evolutionary programming proposed by first author. This new method is applied to Xintan landslide; and the results show that the generalization of the new method is good and it can predict the displacement of landslide very well.

Indoor scale-down test and quick-crusting test were done to simulate sedimentary situation of dredger fill. Those were dosimeter-sediment test and sediment column test. Unit weight, void ratio and water content under different soil-water ratios and different additives of dredger fill have been determined. According to these data, subsidence of dredger fill-grout in standing water can be divided into two stages: fine-particle flocculation stage and mud self-weight consolidation stage, which laid foundation for further study on characteristics of sedimentation of dredger fill.

In order to link the micromechanics to macroscopic behaviour of clays and to establish structured clay constitutive model, the plastic yield function and breakage function have been researched by microstructural sliding model and microstructural crushing model. A new theory called breakage mechanics is proposed for geological material.

Treating the cavern group as a special system, the corresponding relationship between the system and the mechanical parameters of the rock mass is obtained by using the parallel evolutionary neural network FEM. The worst combination of parameters related to the stability of surrounding rock mass is searched out by genetic algorithms (GA). Through sensibility analysis, the synthetical evaluation of the effects of mechanical parameters of soft rock mass on the stability of cavern group is given. Moreover, the key rock mass could be determined to provide the design and construction with further instructive suggestions. The application shows that the method is reasonable and it has the advantages of intelligent and synthetical analysis.

Based on investigation of microstructure characteristics for frozen soil, a new method is put forward to identify and determine micro-crack size in frozen soil. Considering micro-crack damage area as defects and simplified it as equivalent crack according to equivalent crack critical. Thus, the foundation of quantitative calculation and analysis for strength failure for frozen soil is set up. Reference values for three kinds of soils under different temperatures are given; and comparison between calculation results and investigation data shows that they coincided well.

The nonlinear three-dimensional finite element analysis of the 50m deep excavation support during the foundation construction of the north anchor in the Runyang Yangtze River Bridge project has been carried out and discussed. After a brief description of the relevant facts, the numerical model and the input parameters are proposed. Calculations are performed considering various influence factors. Based on the analyses the feasibility of the support system design is evaluated. The outcome of the execution proved the proceeding evaluations.

Soil vapor extraction (SVE) technology is one of the most useful methods to remove volatile organic compounds(VOCs) in unsaturated soil. The principle and technique of SVE are reviewed firstly. A mathematical model of SVE is then established to describe the three principal processes in SVE, namely gas flow in unsaturated soil, phase mass exchange and contaminant transport along with the gas flow. Numerical equations for simulating gas flow and contaminant transport are derived respectively using Galerkin technique and Laplace Transformation Galerkin Technique. Three dimensional finite element computing program is developed and typical three dimensional example is presented and discussed.

A new hypoplasticity model is proposed and verified using tests. An asynchronous staggered iteration FEM method with explicit difference scheme is suggested to solve solid-liquid coupling dynamic elastoplastic problem. The hypoplasticity model is implemented in Biot dynamic consolidation finite element program. The solid-liquid coupling dynamic elastoplastic response of a saturated sand foundation is analyzed; and reasonable results are achieved.

Based on the cyclic triaxial and resonant column triaxial test in the lab tests and the seismic response analysis of finite element effective stress, an analytical method of earthquake resistance on the underground structures in soft soils is proposed. Such factors as seismic action between soil and structures, rising and dissipation rule of pore water pressure and the rule of settlement derived from seismic are considered in the model. Such model is used to analyze the seismic soil pressures of the subway station in Shanghai. Some results calculated by simplified calculation methods are contrasted to the result calculated by the model mentioned above. The foundation is provided for amending the calculation method of seismic soil pressure and improving the anti-earthquake designing level of underground buildings in soft soils.

There is greater difference for calculating result for slope stability factor because of difference of hypothesis for shear action of inter-slice in slice method of the slope stability. Based on computation and analysis of seepage field, pore water pressure of inter-slice is defined in the effective stress method. In the light of hypothesis of Bishop’s force of inter-slice, a new analysis method for pore water pressure of inter-slice is suggested for minimum stability factor of slope. Finally, an example of real engineering shows, the difference of calculated results with different methods and that the new means is practical.

Groundwater seepage is explored, which is the main reason why measured water-earth pressure values on supporting structure is generally very different with that calculated with classic earth pressure theories is explored. Mechanical affects of groundwater seepage on earth pressure are studied. A new calculation charts of water-earth pressure on the foundation pit with consideration of groundwater seepage is presented. This calculation chart is universally applicable to the excavation engineering and the stability of earth slopes in homogeneous soil. It is proved that measured water-earth pressure values on supporting structure is consistent with that calculated with the calculation chart.

Based on the fuzzy theory, the identification algorithm for the concrete thermal parameters was proposed according to observed temperatures inner concrete. The objective function of the fuzzy optimization was presented with the statistical characters of observed temperatures. The inverse problem is formulated as a nonlinear optimization problem, which is then solved by using BFGS method. The statistical characters of identified parameters were investigated because the observed data were uncertainty. The numerical computation shows that the proposed method is able to identify efficiently the concrete thermal parameters while the measurement errors of temperatures are considered.

Considering the characteristics of multi-objective and fuzziness in suitability evaluation of municipal solid wastes landfill site, an approach of multi-layer and multi-objective fuzzy sets for complicated system is presented. The fuzzy pattern recognition model is combined with fuzzy comprehensive evaluation model to evaluate and optimize municipal solid wastes landfill site. In the model, an adapted analytic hierarchy process (AHP) and relative membership function are proposed to calculate respectively the weights of evaluation indexes and the optimal fuzzy recognition matrix. Finally, the proposed approach is successfully applied to assess a given solid wastes landfill site in Shanghai area. Moreover, the procedure can also be applied for evaluation and optimization of the engineering sites for other purposes.

The engineering properties, such as depositing law, grain distribution, permeability and compressibility of the West Lake dredging soil, are studied by room tests. Comparisons of these engineering properties of the dredging soil depositing in room and in sludge reservoir are also put forward. The distribution laws of permeability coefficient, compressibility coefficient, etc. with depths and distances, are concluded. These test results are important for the study of engineering properties of the dredging soil, and can be used to guide the post-processing of the dredging soil in sludge reservoir.

The rheological behavior of the soft clay foundation was incorporated in the study of consolidation. A corresponding finite element program was developed and was used to simulate the consolidation for an expressway ground as a case study. Some parameters, such as the subsidence, distortion and pore water pressure etc., were calculated and the values were found close to the measured ones. The results show that the rheological behavior should be taken into consideration in the simulation of the consolidation of soft ground.

According to Rankine’s theory of earth pressure, and analysis of relationship between active and passive and static earth pressure and displacement of retaining wall, an approximate calculation method of earth pressure considering displacement is presented. The rule of earth pressure varying with displacement presented in this paper is well comparable with the results of the finite element analysis.

In order to consider the cross-sectional non-axisymmetrical characteristic, a barrette is discretised three-dimensionally along its depth and across the barrette. The static equilibrium equation and the Mindlin equation are used to establish the displacement equations for the barrette and its surrounding soils respectively. The governing equation of the load-settlement relationship of the barrette is then derived by solving simultaneously the displacement equations. By using this method, the load-carrying behaviour of barrettes is analysed. It is found that a uniformly distributed shaft resistance is not mobilised across the barrette until the slippage failure of the soil nearest the barrette has been reached. The ratio of length to width has distinct influence on the load-carrying behaviour of a barrette.

In order to settle the basement of deformation simulation and numerical analysis of Xietan landslide in the Three Gorges, the drained triaxial compression creep tests with the constant stress on landslide zone soils have been carried out. Based on those tests and supposed that c, are independent on time and , ,G, D, n , depend on time, a Duncan-Chang E-μ model which depends on time is presented. Through the simulation of test data, the behaviors of k, , , and time are given and 12 parameters in that model is given also. In the end, through contrast of computed curves by model and test data, that model is proved to be suit to such landslide zone soils in Xietan landslide.

It is well known that the chemical data can help us judging the quality of water, but few people realize that it can also tell us the dynamic conditions of groundwater. Based on the monitoring hydrochemical data of major components, trace elements and hydrogen and oxygen isotopic compositions of various springs and the water from drill hole, this paper discusses the hydrodynamic conditions and the flow system of the karst water at Maoba syncline. And the hydrodynamic parameters such as penetrate coefficient, transmit coefficient, flow velocity and the age of groundwater are given. The principles and methods of hydro-chemistry dynamics are applied in this paper to find a kind of parameter analysis method of seepage in karst fractured rock mass. On the basic of theoretical analysis and practice performed with the experimental model a series of significant conclusions concerning the feasibility and calculating efficiency of the method are summarized. Meanwhile, a contrast of k between hydrochemical dynamics method and other methods such as isotopic and the pumping test is worked out.

This paper introduces, analyses and appraises the principle and operating rule of newly and existing earth—filled compaction checking technology. Based on making penetrating analysis, this paper expounds the necessity, mechanical model, the accomplishing ways and newly international preparing advance of developing compaction machine assembling system. The basic principle and working properties of compaction machine assembling system are also described; and that for satisfying basic needs of earth-fill compaction quality in civil engineering (such as quantity of settlement, rate of settlement and so on) the mechanical intensity (such as K30, dynamic rigidity coefficient and so on) should be taken for standard of reference in preparing compaction machine assembling system.

It is based on Biot’s three-dimensional consolidation theory of ideal soil. The compression of the pore fluid is considered in the continuity condition of the flow. And this factor, as a function of the degree of saturation, can be written into the Biot’s two-dimensional consolidation equations. The governing equations are established by using Laplace and Fourier transformation to obtain the initial functions. Then the real time behavior can be obtained by using numerical inversion respectively. The procedure of consolidation affected by the degree of the saturation of highly saturated soil is studied thus the consolidation of the compression of pore fluid is proved to be necessary.

Seamless link between the AutoCAD software and the developed adaptive FEM analysis software AFEAS, has been explored and realized by using object-oriented technique. A simple example of landslide problem is studied to demonstrate the feasibility and advantage of the method.

The paper describes the study for optimum positions of sensors in the shaking table test for subway station structure in soft soil. The deformation features of subway station structure under the transverse vibration is proved by three-dimensional FEM analysis. On the base of the result, it is determined that includes the scope of section that satisfies the plane strain rules and the position of the main observation section. The deformation tendency of station structure is analyzed by plane strain FEM and the optimum positions of sensors in the observation section is determined. The method is proposed on the premise of satisfying the demand of basic information, which can optimize the distribution of available sampling passages. The achievements guarantee the success of the test and can be referenced by the same type test.

In the numerical manifold method (NMM), the most commonly used physical cover functions are not the best choices. Along the procedure of the formation of stiffness matrix, this paper analyses the causes of the non-diagonal entries of relatively huge absolute value in stiffness matrix, when ordinary physical cover functions are used. These extremely large entries can increase the condition number of stiffness matrix to a great extent, especially when stiff spring method is used, which is very universal and basic in the NMM. This paper suggests that well-defined local physical functions, orthogonal the better, be used instead of currently used ones related to global coordinates. This choice can help to eliminate the above-mentioned phenomenon and provide a relatively well-conditioned stiffness matrix. The suggestion is straightforward to implement, causing little changes to currently used procedure, while it affords a lot to improvement of the quality of stiffness matrix. Some examples are analyzed to test the suggested cover functions. Comparisons between the stiffness matrixes based on locally- and globally-defined cover functions show that the previous ones generate better stiffness matrix in terms of condition number.

For the existing remained slip force method, there is no description about how to consider the effect of rainfall, so there have many problems when we use it. To solve these problems, we categorized the effects of rainfall systematically based on the existing achievements; and have attempted to give out the ways of determining the effects quantitatively; then we added the quantitative relations into the existing formulas and programs. The application of the improved method indicates that the calculated result conforms to the reality.

The limit state equation is fitted by using neural network; the structural reliability is calculated by adopting geometric method; and the calculation formula of the geometric method is deduced based on neural netword. Finally, the precision and efficiency of the proposed method are compared with other methods; and it is applied to a practical projecta.

Based on analyzing the mechanism and characteristics of the dynamic consolidation by drainage (DCD) for soft clay foundation, a DCD construction technology suitable for soft clay foundation is proposed.

The roller-compaction tests on soil-stone mixtures with two kinds of different paved thicknesses, three kinds of added water amounts and five kinds of vibrant compaction times combinations, are carried out and discussed. In terms of testing before and after compaction particle constitution, dry and wet density, settlement and deformation modulus, a set of optimum parameters are gained as control parameters on field-construction. In addition, some corresponding measures and suggestions are proposed by analyzing the test results.

By use of concepts of pointer and derived type in FORTRAN90, a linked list which carried out a dynamic memory allocation for global stiffness matrix and enforced its flexibility is made. Consequently, it avoids lots of shortcomings in the array memory and the old method of forming the global stiffness matrix. This method can be very easy in data processing of the global stiffness matrix such as insert, delete etc. and be invariability in the structure of the array. At the same time the method can save more EMS memory than the common half-band memory. So the method is especially suitable to analyzing the extraction and support with the geotechnical engineering in the 3-D FEM and can enormously reduce times of solving equations.

The construction scheme of tunnels passing through landslide area and fault zone of the repair tunnel for Changkou water tunnel of Zhangjiu River water diversion and supply project in Kunming is introduced in detail, including such contents as description of tunnel collapse to ground surface, ground settlement pit treatment, collapse body treatment in tunnel, constructuon procedure and technical measures of pass through landslide area. Construction practice has shown that the tunnel collapse treatment scheme is reasonable, reliable and effectual.

An experiment on foundation improvement by dynamic consolidation in loess region was made, before and after the experiment all kinds of in-situ tests were made in order to make a conclusion of the efficiency of the way of foundation improvement by dynamic consolidation; and the effective depth of improvement of founfation, is calculated so as to make an example for such engineering.

Combined with the practical engineering problem of Dajuyuan-Kexueguan interval tunnel excavation of Shenzhen metro by non-water lowering with adjacent pipeline, the construction scheme is illustrated; and evaluation standards of buried pipelines are given. Firstly, the effect of interval tunnel excavation on the buried pipelines is simulated by means of centrifugal model test. Secondly, the 3-D FEM coupling analysis model of tunnel supporting-soil-underground pipeline is established. Deformation and internal force of buried pipeline are analyzed specially by numerical simulation of tunnel excavation and also the safety of the pipeline is forecasted. The rationality and reliability are proved by comparing the results of centrifugal model test, numerical simulation and in-site measurement. Theoretical base and guidance are provided for real engineerings and some meaningful results are achieved.

On the basis of static loading test of pile and composite ground for different soil conditions, a method for determining the efficiency factor of the soil bearing capacity among piles in Handan city is presended by analysing and calculating.The results can be used for the design of composite ground.

Owing to aerobic tank overtopping dam resulting in dam break, the drainage-seepage ditch on Zishan dam and non-sandy concrete surface of its ash-ward slope were partly damaged, that resulted in drainage amount was increased and ash was leaked sometimes on the exit of the drainage-seepage ditch and the cone of leak ash and water was formed on the inlet, a lot of cracks appeared in the beginning at the non-sandy concrete surface (rigid body) and in the sequel at the ash-ward slope surface (flexible body). The cause of formation of crack should be due to landslide. On the precondition of carrying out measures of saving and protecting the dam and choosing preventing and curing project, the feasible tests of filling grouting were done. The cracks were dealt with using the grouting. Then the dam had been gone through the very strong rainstorm in the current year. As yet, the dam was running normal. The results of grouting were better.

The meshless natural element method(NEM) requires only nodes and a description of the external and internal boundaries, and no element connectivity is needed totally or partly. Therefore, meshless natural element method can be widely applied to crack propagation problems, elastoplastic analysis of materials and large deformation problems. Based on the summarization of the present literatures, the nature element method ,which possesses the characters and advantages of the traditional finite element method and other meshless methods, has been studied further. And its application to elastoplastic problems is proposed and the basic principles of meshless natural element method are presented too. Finally, some special problems are given to verify the program designed according to the principles.