Researches On Seepage-Stress Field Coupling And Its Applications

If there is any water, stress field and seepage field will affect each other, will be in a couplingdynamic drift situation and form a coupling relation. At present, seepage analysis and stress analysis are calculated separately in research about the earth dam, hardly researched from the view of seepage-stress coupling. In this case, considering two fields as a system, it is essential to research and discuss the coupling problem between seepage field and stress field. On the basis of summarizing the the existing research, the thesis mainly covers the following aspects:1.The thesis first introduces soil moisture potential theory, then research and discuss the basic unsaturated seepage theory, the relation of soil-water characteristic curve and seepage coefficient and the confirmation of the material unsaturated seepage coefficient. The 3D saturated-unsaturated equations of porous media and the FEM are induced. Furthmore, direct seepage and stress coupling method and undirect seepage and stress coupling method are introduced, and their equations and FEM are given.2.The two-dimensional FEM format of Biot's consolidation theory is detailedly deduced. two kinds of equivalent plane strain methods in drain pile ground are introduced. Based on the treatments of soft clay in tailing dam of Chengmenshan copper mining located in Jiangxi province, by using Modified Cam-clay Model Coupling Biot Theory, numerical simulation is carried out in drain pile ground during the construction of the tailings dam. Based on numerical results, relationships between the displacement of foundation and time, excess pore pressure of foundation and time, are analyzed. Comparing numerical results with observation by the displacements of the foundation, those calculated results have a good agreement with those observed results. those results gained by numerical method may provide reference to engineering practice.3.The principles of limit equilibrium methods (LEM) and shear strength reduction technique(SSRFEM) are introduced on stability analysis of soil slope under Seepage. the finite element modle under Coupled Deformation and Seepage Fields is developed, which takes into account the effect of plastic deformation, saturation and void ratio on the properties of soil materials, the effect of water and soil interaction and the extended Mohr-Coulomb failure criterion. the response of the soil slope of the Dongting Lake is simulated during rapid drawdown of water level. The results show that seepage upraises the critical slip surfaces. Furthermore, critical slip surfaces, saturation lines and safety factors by two ways are pretty close. the SSRFEM is more applicable to evaluating global stability of slopes than LEM.4.Soil slaking deformation and its mechanism are analyzed, and its calculating methods is discussed. And then, through some cases,applying nonlinearity elastic modle, give the discussions on the problems such as adding load in stages, influence on stress field and displacement field by slaking deformation, changes of stress field and displacement field by slaking deformation, changes of stress field and displacement field resulted from soil slaking deformation.