Study of soil structures strength and stiffness loss based on thermodynamics and continuum mechanics

Based on the theory of damage mechanics and porous medium continuum mechanics, a solid skeleton strength degradation model for internal erosion of earth structure is presented in this paper. Saturated soil is considered as a mixture composed of matrix skeleton and porous space, the latter being filled by fluid which consists of a mixture of water and eroded particles. With these eroded particles being carried out with fluid, porous space in earth enlarges, and the effective stress area of solid skeleton decreases, which leads the effective stress acting on the solid skeleton to increase. This process also involves earth structure stiffness loss and strength degradation. This paper presents a constitutive model and sets up the relations between the strain and the internal erosion damage variable using thermodynamics and damage mechanics.