DIFFERENT DISCRETIZATION METHOD USING IN COUPLED WATER AND HEAT TRANSPORT MODE FOR SOIL UNDER FREEZING CONDITIONS

A coupled water and heat transport mode is established, based on the Richards equation to study the water flow and heat transport in soil during a freezing process. Both the finite difference and finite element method are used in the discretization respectively. Two different computer programs are written and employed to simulate an indoor unidirectional frozen test. The freezing depth, freezing rate and temperature variation are compared among the real test, the finite difference calculation model simulation and the finite element calculation model simulation. The result shows that: the finite difference method has a better performance in freezing depth simulation and the finite element method has a better performance in one-dimensional freezing stability simulation.