GOVERNING EQUATIONS CONSIDERING PHASE CHANGE FROM SOLID TO FLUID OF SOIL GROUND BASED ON THREE-PHASE SATURATED SOIL MODEL

Abstract

 When soil liquefaction occurs, the stiffness of the soil skeleton is reduced, and the soil behaves like a fluid composite of soil particles and pore water. In this study, we formulate an expression for the phase transition of soil from solid to fluid, assuming a mechanical process similar to that of internal erosion, and derive the governing equations, including the conservation of momentum. It is confirmed that the proposed equations can be reduced to the Navier-Stokes equations under a hypothetical situation. Numerical analysis of the one-dimensional model and simulation of the centrifuge test results are performed using the proposed method. As a result, it is shown that the proposed method can analyze both solid and liquid phases without any inconsistency and can represent the natural phase transition.