AN ELASTO-PLASTIC DAMAGE MODEL FOR SATURATED AND UNSATURATED GEOMATERIALS
饱和和非饱和介质的弹塑性损伤模型

In this paper, geomaterials are viewed as multiphase porous media consisting of solid, liquid and gas phases. Emphasis is put on the simulation of the degradation and softening properties of geomaterials as a whole where all phases participate in the deformation. An elastoplastic damage model is proposed in the frame of the Theory of Mixtures. The feature of this model is to using the superimposed continuum model to simulate heterogeneous and non-uniform geomaterials. Through the adoption of fraction parameter m~D, the progressive failure and softening properties are recorded as the result of mass redistribution among different solid phases. Similarly, the partial saturation properties are represssed by the relative mass Content of each liquid and gas phase and the interchange among them. Thus makes the damage model possible to consider the influence of the existence of pore fluid and the degree of panal saturation. Besides, finite element implementation is also discussed and a specific-purpose finite element program is worked out. As an example, analyses are conducted to simulate the progressive failure and softening properties of a conventional triaxial partial-saturated specimen.