Numerical Simulation of Sand Migration and Seepage Flow During Seepage Failure by CWENO Scheme

Abstract

When sand reaches the quick condition, it boils and behaves as a fluid because the effective stress vanishes, while the sand can be solid before the seepage failure. This paper proposes a numerical method to simulate the behavior of the sand before and after the seepage failure, during which it experiences the phase transition from solid to fluid. In order to analyze the fluidized sand, Eulerian formulation is applied to the governing equations, i.e., the continuity equations and the equations of motion of the seepage water and the sand. They are categorized into a system of hyperbolic partial differential equations, and the CWENO method (Central Weighted Essentially Non-Oscillated method), which can achieve stable and accurate solutions of hyperbolic systems, is employed. Herein, the seepage failure induced by an upward seepage flow is simulated after the accurate computation of Darcy flows is verified. The numerical results have shown that the computed velocities of the seepage flow and the sand after the seepage failure provides a good agreement with the theoretical solutions and that the proposed method can successfully predict their behavior during the seepage failure.