2. Introduction

This document presents the L&K rheological model developed at CIH by F. Laigule and A. Kleine. It is an elasto-visco-plastic model dedicated to rocks. The specificity of elastoplasticity lies in the modeling of a non-linear behavior in the pre-peak phase and a softening post-peak behavior. Viscosity characterizes the effect of time on the behavior of the rock. The initiation of each of these phenomena is triggered as soon as a threshold is crossed. The behavior associated with each phase is described by the evolution of these various thresholds governed by plastic or viscoplastic work hardening functions.