Large Deformation Analysis in Geomechanics Using CIP Method

Abstract

A numerical method is developed for prediction of large deformations associated with a geomaterial flow. The geomaterial is modeled as a viscous fluid, where a Bingham type constitutive model is proposed based on Mohr-Coulomb's failure criterion and the equivalent Newtonian viscosity is derived from the cohesion and friction angle. These two parameters are very important factors for the behavior of geomaterials. In solving Navier-Stokes's equations, a constrained interpolated profile (CIP) scheme is utilized. The numerical method developed in this paper is used to simulate a 2-dimensional gravitational flow in order to check the performance of the constitutive model. The method is also applied to two real slope failures. One is due to heavy rain and the other due to earthquake. In the analysis of the slope failure due to earthquake, simulated velocity of ground flow, displacement and elapsed time are compared with observed results. In the case of the analysis of the slope failure due to heavy rain, a previous study about the slope failure using finite element method (FEM) is firstly introduced. The method used in the previous study, however, could not describe the subsequent ground flow after the initiation of slope failure. Therefore, the method developed in this paper is applied to simulate the ground flow.