The deformation of natural clays is induced due to the damage of structure. The total deformation consists of 3 parts, i.e.elastic deformation of structure body. plastic deformation due to sliding in the structure plane and irrecoverable deformation due to crushing of structure body. The sliding yield surface is considered as isotropic hardening and rotating hardening bounding surface. The plastic modulus is interpolated using the ‘real stress’ and ‘image stress’ on the bouding surface. It is stipulated that damage deformation occurs under loading or inverse loading conditions rather than under unloading condition. The bounding surface masonry model is developed and verified using test data.

Based on the test data obtained by truly triaxial apparatus of Tongji University and Kirkgard & Lade, and Ohta-Sekiguchi model，an anisotropically elastoplastic model of Shanghai soft soi1s which is composed of shape function. yield function stress-strain relation, is presented. In order to prove its reasonability. This model is also examined by theory and test data, Finally， parameters of soil for model in Shanghai are given.

The stabilized light soil (SLS) is developed after another kind of expanded polystyrene (EPS) used in embankment。 Due to the feature of lightweight the load of SLS filled embankment can be sustained by soft foundation without any treatment。 This paper deals with the stability analysis and settlement calculation for the SLS filled embankment, which is based on the reference【1】。The analysis and calculation results are compared to that of the embankment filled with common material。 Based on it。 the design method for such kind of embankments is also discussed; it will promote the further application of this lightweight material to engineerings.

Parallel computing is becoming the strong trend of solving large scale geotechnical problems。Taking the scheme optimization of the soft-rock replacement in Shuibuya large cavern group for example, parallel computing for the scheme of optimization is discussed。 The following problems such as the parallel programming modes, programming method， tasks dividing data communication and load equilibrium are analyzed。The parallel computing for the scheme optimization of soft-rock replacement is successfully accomplished in the personal computers which run in the windows operating system。The final results indicate that the linear speedup ratio is almost achieved, accordingly the computing speed and efficiency of the scheme optimization is promoted greatly。This paper provides an important reference for the application of parallel computing in the geotechnical engineering.

In order to investigate the working mechanism of composite foundation with rigid piles, two tests of composite foundation with 9 piles were conducted. In these tests, pressure cells were embedded in the soil to measure the vertical stresses at different depths, whereas stress gauges with vibrating strings were installed in the piles to measure their axial forces, which can be further used to estimate the pile shaft friction. The load was applied step by step and the stresses in the soil arid axial forces in the piles were measured for each load step. The test results show the entire process of load transmission; and they can provide useful information for the designer in understanding the bearing characteristics of this type of composite foundation.

Concrete-cored deep cement mixing(DCM) pile is a new kind of composite pile used in soft ground engineering: it has many advantages such as simple in construction. little environmental disturbance, high bearing capacity，low settlement and less project costs. Based on the results from static loading test, the elastoplastic finite element method is used to analyze its much an ism under axial load, including pile-soil stress ratio (PSSR), load transfer. load distribution between pile-core and p ile-socket。 plastic area in soils and pile head settlement characteristics, etc.

According to the principle of generalized plasticity. the constitutive equation of subloading surface cyclic model is firstly formulated; and the loading criterion and the identification of material parameters are built. The applicability of the constitutive equation to the prediction of real soil deformation。Including massing effect and ratcheting effect, is verified by predicting monotonic and cyclic loading behavior of sands under several stress paths.

Based on the simple arc-slice analysis method for the whole stability of soil-nail braced structure, calculation of integral stability of a building foundation pit with soil-nail braced structure in Beijing has been carried out by using the genetic algorithms. The results show that the most dangerous sliding-plan will move backward after soil-nail treatment and that genetic algorithms c:in determine the most dangerous slide plane and the corresponding coefficient of integral stability accurately and effectively. Besides, it can avoid getting in local minimum in optimal design. Therefore it is proved that this method is credible and accurate.

The geocells with vegetation are used for control I ing erosion of rocky slopes. The stability analysis method of geocell is proposed based on field experience and theoretical consideration of their failure modes. The influence fac)ors on stabil itj' df the geocells, such as slope angles, spacing of the fixing pins, depths of geocells and the geogrids being placed at the interface between the geocell and slope, are analyzed. The main problems in geocells installation processing are discussed. The results important to guiding design and construction are obtained.

Because of limitations of deformation measurement method。 it was difficult to research the in influences of soil specimen deformation caused by end restraint and end contact in triaxial test before. By digital image processing technique, the axial deformation and radial deformation of triaxial specimen are measured directly. Making a comparison between the results with traditional method and digital image processing technique, these influences are determined quantitatively. Finally, it is concluded that using the digital image processing method measure the local deformation directly can avoid the influence of the end restraint arid end contact to the deformation of soil specimen.

A series of artifical calcareous sand - steel interface direct shear tests was performed. It shows that the contact relation ship of the interfaces is frictional; and the curves of shear - normal stresses ratio vs shear deformation under different normal stresses are almost identical. Negative dilatancy of the sand under constant normal stresses is quite large. Shear strength under constant volumetric shear test is far below that under constant normal stress condition. Load and unload curves are almost superposition. There is a trend of shear strength debasement after cyclic shearing. And the wet friction coefficient of the interface is less than the dried one.

A case study on the application of field pour concrete thin wall cased pile technology in a municipal road with high earth fi11 in nanjing Dachang District is conducted. A series of field detection and in-situ test have been performed: the results show that the bearing capacity satisfies the design capacity and the use of this style pile is successful. The low strain test shows that the pile quality is good. So the field pour concrete cased pile with vibrated steel tube mould technology is an effective and economical technology for soil improvement.

In order avoid the occurrence of ‘rubbery soil ’ in soft clay during the construction of dynamic consolidation method ( DCM). An innovative idea of using well dewatering technique to accelerate the dissipation of excess pore pressure and the consolidation of soft soil and to improve the efficiency of dynamic consolidation has been proposed. the in-situ test has been studied to verify the effectiveness of treating the soft clay underlying hydraulic fill sand by DCM combined with well dewatering on a container terminal in Shanghai; and soil deformation. pore pressure. time effect of soft clay strength have also been analysized and discussed. The successful achievement of the filed test and the large-area application show the feasibility of DCM combined with well dewatering in the treatment of soft soil and enriched the contents of the DCM and well dewatering technoloty； and also further broaden the application range of DCM and well dewatering. All the relults in the test are referential to some other similar projects.

Based on the rainfall seepage process analysis ,a rainfall conceptual model is presented; and the method of how to calculate seepage field in a slope under diverse rainfall patterns by numerical analysis of seepage flow through the saturated and unsaturated soils is proposed .Analyzing results show that the rainfall seepage process is affected greatly by the initial seepage field; and initial moisture content has some influence upon the expansion of wetting front. If it’s raining hard rainwater seeps so slowly that shallow soil keeps some suction. Although rain stops the seepage field will change greatly.

Element-free Galerkin method (EFGM) is especially suitable for analysis of the frictional contact problems of rock structures because no element connectivity is needed. Based on EFGM, the penalty parameters are introduced on the cracks. Through the iteration process, the true stress states can be obtained and the contact criterion is applied to determine that the interfaces are open or closed. Numerical examples show that this method is effective .

The behavior of geosynthetic reinforced embankment on soft clay has been explored using the technique of centrifugal and numerical modeling. During the consolidation of foundation soil, the strain and stress of soil and geotextile are analyzed in the two ways above mentioned respectively. Two series of results are studied by the comparative method and show that ( I ) the work principle of reinforcement is its tensility limits its own deformation and reduces horizontal displacement of soil nearby through friction; (2) reinforcement dwindles and separates the regions of high shear stress level in embankment-reinforcement-soil system, therefore improves the global stability; (3) reinforcement reduces the whole deformation of embankment and foundation; (4) the mobilization of reinforcement’s tensile strength is low and the mobilization of shear strength in the interface is about 23.8 %.

Taking material nonlinear characteristics into consideration, some tentative analysis of the flexible foundation and composite ground has been done by means of finite element method. For this kind of composite ground, some basic regularity of the load distribution, load transferring and variation along depth, deformation characters, and so on, have been obtained.

On the basis of thermodynamics, the physical mechanism of biodegradation—caused settlement of municipal solid waste is discussed. Furthermore, the biodegradation—caused settlement is identified; and its calculational model is initially established. According to correlative observed data, the biodegradation-caused settlement of certain sanitary landfill of Hong Kong is estimated with this method. The results are compared with its observed total settlement.

The design method of composite pile foundation is introduced. Progress of total settlement of composite pile foundation is analyzed; and the method of settlement calculation is presented. The ground settlement due to the load shared by pile group is calculated with layerwise summation method based on Geddes stress method; and the ground settlement duo to the load shared by soils under pile cap is calculated with layerwise summation method based on Boussinesq’s deformation formula; the summation of two settlement above equals the total settlement of composite pile foundation. The design and settlement calculation methods have been applied to certain building with composite pile foundation; the results show that the pile number is decreased about 1/3, and saved cost 35%, while the total settlement increased a little.

The fuzzy model of multi-objective system is applied to optimal selection of dynamic compaction patameters so as to realize quantization of qualitative problem.The case shows that the fuzzy optimization method is more scientific and reasonable than others.

The soil nailing retaining is widely used in China, but the principle and calculating method of soil nail are not so perfect. It is necessary carry out field test to consummate the theory of soil nailing. The testing includes horizontal displacement and soil nail tension etc. The distribution laws of deep excavation horizontal displacement and soil nails tensile forces are obtained through the field test. Some important conclusion are reached: I I I The maximum horizontal displacement occurs on the top of deep excavation; ( 2 ) Along whole depth of deep excavation, the maximum soil nail tensile forces occur in the range of middle depth; 1 3 I The maximum soil nail tensile force occurs in the middle range of soil nails along its length. The curve which is formed by positions of maximum tensile forces of soil nails may be the most dangerous sliding curve.

Confirming initial earth of rocks is necessary to design and construct geotechanical engineering such as underground cave and slope.An approach analyzing initial earth stress is presented.That is means of combining displacement function method and FEM to simulate initial stress field.The result of ecample indicates that this method can simulate the initial stress field;and offer an equivalent method how to apply load on model for FEM analysis later.Therefore,this method has good practicability.

The genetic algorithm was used in optimal desingn of deep-mixing piles.The cost of deep-mixing piles in one unit area of foundation was taken as the objective function.All the testrains were listed following the corresponding specification suggestions were proposed and the modified genetic algorithm was given to deal with the problems of excessive computational cost and premature convergence.software system of optimal design of deep-mixing piles was developed in visual c++.The effectiveness of the optimal method was proved by an application example.

The principle of minimun energy dissipation and its general procedures to establish strength criterion of materials,have been intoduced.With the widely accepted viewpoints that strength criteria express the energy accumulation of material and utilizing the viscoelastic fracture theory the strength criteria for crack creep are deduced.For the sake of contrast these viscoelastic equations are also obtained directly from strength criterion of elastic fracture theory in form of strain energy density.Therefore creep stability of fracture in several kinds of viscoelastic material is analyzed

The paper analyzes the sliding range and sliding surface of an old landslide by investigating an old sliding slope. In addition, back analysis is used on shear resistance parameters of slide surface. Primary treatment design of the old slope is carrying out. Measure for preventing water is not carried out at present. the quota of anti-slide come down further. Calculation analysis of stress of soften sliding surface is carried out. According to the investigation on K89-95, the consequence resulted from disobeying the principle of selected route of engineering geology is thought again.

The shape features, structural features and mechanism of a landslide are deeply analysed. A new synthetical method for reasonably determining the shearing strength of landslide is developed. On the basis of the mechanism of landslide and the suitable conditions of each harness measure, through the comparing, Choosing and optimum analysis of many schemes, a harnessing scheme of both safety and economical is proposed.

Based on Geddes stress solution, calculating 3-D stress of arbitrary point in group piles according to superposition principle ,and based on Duncen-Chang constitutive model, to calculate settlement of arbitrary point in group piles according modified layered summation. then, establishing set of equations according to basic point method[1] and coordinative relationship of loading and deformation of group piles foundation, to obtain the loading-settlement relationship of group piles. To compare with general method based on Geddes stress solution, three parts have been improved, they are as followings: (1)adopting Geddes 3-D stress solution, its effect on settlement of group piles can be calculated;(2)the constitutive model(Duncen-Chang model) is used to study the settlement of pile, the nonlinear character of soil can be considered.;(3)using modify layered summation, the layer character and lateral deformation of soil can be computed. Therefore, the method that proposed in this paper is more perfect in theory, amount calculation is moderate and apply to engineering practice.

The method of multi-layer recursive modeling for predicting slope displacements is presented.The state(output) forecast of the dynamic system is divided into time variable forecast and state(output)forecast based on the former.The time variable characteristics in the forecast system can be fully considered.The modeling of multi-layer recurrence and the forecast method are presented.The engineering example shows that the method has better precision and practical values.

Based on the excavation of Chaodongyan tunnel， a numerical analysis concerning the influence of karst caves in the top of tunnel on stability of the surrounding rock masses is carried out by using the ANSYS software system; the yield initiation is assumed to occur following Druck-Prager failure criterion. The results of numerical modeling show that the stability of the surrounding rockmass of the top of tunnel increases with increace of the distance between the karst cave and tunnel; and reduces with increase of the karst cave size. There is a good relationship between the deformation of the surrounding rockmass and the distance from the karst cave to tunnel. The limited distance between the karst cave and tunnel is about 2—3 times of the diameter of karst cave. The character of stress field and plastic district of the tunnel surrounding rock masses is discussed.

Some parameters of the rock mass, such as elastic modulus, intensity parameters, etc., are very important to underground cavern design and construction. Lots of cost, materials and efforts are needed if field test is done. Sometimes, the result of field test is not very good. In this situation, application of the inverse analysis theory can overcome the disadvantages that the field test has. Using this theory, displacement that can be got easily by field test, is used only to calculate the needed parameters. There for the direct displacement inverse analysis is used to calculate the rock parameters for Shibeiling tunnel.

The space statistical characteristics of a smooth stochastic field are elaborated. On the basis of concept of smooth stochastic field ergodicity, conditions that soil strata are satisfied with ergodicity are discussed; and equations of calculating space mean variance and correlative distance are deduced. Finally, the influential factors of calculating space mean variance are analyzed combined with a static cone penetration data.

The patterns and mechanism of interaction between reinforcements and soils vary with the reinforced structure as well as different parts of the same reinforced—structure. thus the corresponding testing method of interface parameter between reinforcements and soils (IPRS) are different. Based on the updated researches about testing methods of IPRS at home and abroad, and in view’ of the requirement of engineering practice, a criterion used to select reasonable method for testing the IPRS is set up in accordance with the relationship between reinforcements and soils; and some references are given in obtaining IPRS both for reinforced engineering design and researches.

An adaptive FEM analysis software for seepage problems has been developed with the object—oriented technology and the language C++. In the pre—processing of the software system, the object modeling is convenient to be implemented; and the interface of the system is friendly. By embedding the adaptive FEM analysis module, the system has the advantages of standardization and objectivity in computation results, which means for the definite problem, only one solution can be obtained from different users if the computation tolerance is properly defined, what’s more, the post—processing is visualized and intuitionistic. Finally, an example of seepage in earth dam is given to show the application and merits of the software.

Based on one dimensional consolidation theory and Voigt-Kelvin viscoelastic model, the performance of ground settlement at primary and secondary consolidation phases is investigated. Analysis results show that the relationship between settlement-velocity and settlement of ground is approximately linear. Based on this linear relationship a method is proposed, which provides an estimation of coefficient of consolidation and of the settlement components including immediate settlement, primary consolidation settlement and secondary consolidation settlement of the ground. An application of the method to a practical case is presented

The multi-coupling in the dynamic consolidation method(DCM) for reinforcing foundations is analyzed. Integrated considering factors of liquid, solid, dynamic resulting from rammer bump into ground, the solution method and iterative format are given based on three—dimensional finite element method. Though coupling analysis of an actual project, the variational rule and distributing character on displacement, stress, and contact stress are obtained. The results have shown good agreement with those data of the actual project. The coupling method proposed is applicable to dynamic consolidation method and the similar dynamic questions.

The causes of culvert damage is introduced . Defect of calculation of earth pressure on the top of culverts based on highway standard or railway standard is elucidated. A novel calculation method is proposed to calculate the earth pressure on the top of culverts. The calculation results show that the defect of calculation based on highway standard or railway standard is avoided by using this novel method.

The creep mechanism of rockfill is studied based on the creep test of large scale compression apparatus with breakage measurement .The main factor causing the creep deformation is theater the pores are fillde by the movement of smaller breakage rockfill under the effect for continuous compression deformation .The breakage of rockfill can be divided into two types ,one is the breakdown under the main compression deformation deformation and the other is Anderson the creep strain .The breakage result in the change of rockfill gradation,furthermore,the loon-term deformation is then induced .

Adopting the method of structural mechanics and UNWEDGE program, stability of top staff tor a large underground cavern under single discontinuity, groups of discontinuities and fragmentized rock mass is discussed so as to obtain the critical stable thic1:ness and the feature of potentially instable blocks, which can be beneficial to guiding excavation and timbering.

Point load test is one of the tests for measuring the strengths of rocks. Compared with the test machine method, it is more economical and simpler; but, due to the I imitations of many practical factors, its exparimental result is not higher in accuracy. Therefor, its adaptability is discussed from several aspects.

Jinhua Mansion was one of the early deep foundation pit project with systematical supervision .The pit supporting design has been adjusted with supervision and has successfully finished.In order to prove the adjusted results,by using finite element method the simulation calculation and analysis for the pie have been carried out.