Elastic - Viscoplastic Theory In Slope Stability Analysis

Some slopes are made up of clay or softrock in the earth, these materials have evident characteristics of rheology, thus the slopes' deformation are marked in it's history. In the process of resulting these questions the traditional elasticity and plasticity are incapable, but the rheology has particular power to do this. In this article the rheology will be used to analyze the stability of softrock slope.In a general way, the materials of slopes are very complex, and it's structures are scattered very differently, also the shapes and the loads of slope. Under these conditions, a direct solution can't be achieved easily, so we can only get a approximate solution, none but numerical method can help us to do this. There are many methods such as FEM(Finite Element Method) BEM(Boundary Element method) , FDM(Finite Difference Method) . DEM(Distinct element Method) FLAC(Fast Lagrange Analysis of Continue) NMM(Numerical Manifold Method), ISEM(interface Stress Element Model) in this field. The ISEM is found by prof Zhuo jiashou of Hehai universty. In this article the ISEM is used to solve equilibrium equations and get the stress and strain of slope.The physical model of slope is Bingham's elasticity-viscoplasticity model. The equation of physical model are programed in Fortran PowerStation V4.0. Through this program the stress and strain of slope will be solved.Through analyzing the slope of materials storage yard of Yuxi steel stock company, two main pieces of conclusion are drawn:First, the digged slope is steady in the mass.Second, the cohesive soil and the full weathering shale on the top of slope have a biggish displacement, some of them may dropping one day. So the style of digging from top to bottom with 60° gradient is risky and the stepwise digging is more necessarily. Concretely, the slope can be digged for two terrace with different angles. The position between two terraces may be the bottom of full weathering shale.Above conclusions are better to the design and construction via the exam by Practice.