An Efficient Model for Numerical Simulation of the Mechanical Behavior of Soils. Part 1: Theory and Numerical Algorithm

Abstract

A numerical model to simulate the mechanical behavior of soils is presented in this first part of the present work. This paper reports some advances obtained in the first stage of an ongoing research, which aims to develop a robust and efficient algorithm for consolidation analyses of saturated/unsaturated soils. Hence, the present work is mainly concerned with basic issues, such as efficiency of the finite element formulation and accuracy of the constitutive formulation. Since geotechnical materials exhibit elastoplastic characteristics, the theory of plasticity is applied here by means of the critical state concept using the Cam-Clay formulation. The constitutive equation is integrated using an explicit algorithm where the strain increment is divided into a number of sub-steps defined automatically by the numerical scheme. Eight-node hexahedral finite elements with one-point quadrature are employed in the spatial discretization of the geometrical domain. In order to avoid excitation of spurious modes, an efficient hourglass control is utilized in conjunction with a corotational formulation, which also contributes to the treatment of geometrical and physical nonlinearities.