降雨条件下土坡三相流耦合模型验证与分析

Verification and Analysis of Three-Phase Coupling Model for Soil Slope Under Rainfall Conditions

基于非饱和土力学的基本理论,建立了考虑孔隙介质可压缩性的二维非饱和土坡固-液-气三相耦合控制方程,利用COMSOL multiphysics软件的PDE平台,将所建立的耦合控制方程的数值模拟结果与经典Liakopoulos砂柱排水的试验结果进行比较,验证了所建立的三相耦合控制方程的正确性,并讨论不同因素对渗流场和位移场的影响.模拟结果表明:渗透率ks对降雨渗流过程的推进起阻滞作用,同时延缓了非饱和土坡的变形,但影响较弱.进气值系数对非饱和土坡变形沉降的过程有一定影响,但总体影响也较弱.

Based on the basic theory of unsaturated soil mechanics,a solid-liquid-gas three-phase coupling control equation for two-dimensional unsaturated soil slopes was established by considering the compressibility of porous media.The numerical simulation results of the established coupling control equations based on the PDE platform of COMSOL multiphysics software was compared with the experimental results of the classical Liakopoulos sand column.The established three-phase coupling control equation was verified,and the influences of different factors on the seepage field and displacement field were discussed.The simulation results showed that the permeability can slightly retard the rainfall seepage process and delay the deformation of unsaturated soil slope.The air intake coefficient has a slight impact on the settling process of unsaturated soil slope.