Stability Analysis On Slope Soft-soil Foundation Embankment

Slope soft-soil foundation is a kind of inclined soft-soil foundation on the surface or bottom surface. Slope soft-soil foundation rich in the damp rainy mountain area, because of natural conditions such as topographic relief and plentiful rainfall. With the large scale construction of road and railway in the damp rainy mountain area, subgrade on the slope soft-soil foundation becomes general and important. Bad treatment will seriously affect engineering quality and progress. In order to raise engineering quality and improve subgrade construction techniques, the basis is to comprehensively master stability and deformation problems of subgrade on slope soft-soil foundation. Therefore, this text mainly studies on the stability and deformation characteristics covering the following aspects:1) There are many methods analyzing on stability of soft-soil foundation. This text using Sweden arc method, Swedish slice method and Bishop method studies on minimum safety factor and the shape and position of most dangerous sliding surface with various formation slope m , different soft-soil thickness D ,different embankment height H , and different soft-soil strength parameter (c,φ) . Based on the above study results, this text obtains parametersensitivity analysis and identification standard evaluating stability of slope soft-soil foundation subgrade.2) Traditional stability analysis of foundation mostly use material and structural strength of subgrade under limit state, hardly considering deformation controlling problem. This text bases on the plane finite element calculation on basic properties of slope soft-soil foundation, analyzing relationships of formation slope, soft-soil thickness, embankment height, and formation strength with deformation coefficient and relevant displacement, tress, strain; also introduced deformation coefficient into foundation stability evaluation. It supplements traditional safety factor method and improves foundation stability evaluation.Safety factor method is the principal method used now. It mainly analyses shear strength of foundation, hardly considering foundation deformation properties' effect on foundation stability. Especially when foundation deformation effect greatly on upper building or upper building requires foundation deformation strictly, merely satistfying strength safety factor is inadequate, and should consider foundation deformation. Thus, identification standards evaluating stability of slope soft-soil foundation subgrade include not only traditional safety factor but also foundation's deformation.