水流入渗和气体驱替过程二维问题的耦合求解

采用孔隙介质力学分析方法,把土体骨架、孔隙水和孔隙气体分别作为独立的研究对象,结合孔隙水和孔隙气体在气、液交界面上的力学条件建立耦合方程,研究非饱和土中孔隙水的入渗和孔隙气体的排出过程,为水流入渗问题的求解提供了一种新的方法。将此种方法应用于二维水流入渗问题的数值求解,利用简单的工况校验了这种计算方法的可靠性。通过对砂体和粉煤灰断面进行的二维水流入渗计算表明,孔隙气体的排出过程影响孔隙水的入渗运动。

2-D numerical simulation for the process of water infiltration and pore gas expelling

The equations with coupled boundary condition on the interface,which govern the process of pressured water infiltration and pore gas expelling in unsaturated soils,are established in this paper based on the equilibrium analysis for pore water and pore gas separately. It presents a new method to solve the problems of water infiltration. Examples of applying the method to 2-D numerical simulation of the process of pressured water infiltration in dry sand and fly ash are given. The results of the simulation show the influence of pose gas expelling on the water infiltration process. Comparisons of numerical simulation by the method and theoretical solution for one-dimensional problems are illustrated. It shows that the proposed method is accurate.