土水特征曲线为直线的非饱和土一维固结计算

Computation of one-dimensional consolidation of unsaturated soil with linear soil-water characteristic curve

基于Bishop有效应力原理,将土水特征曲线与固结方程相结合,提出土水特征曲线为简单直线型的非饱和土一维固结的计算方法.假定土体固结分为2个阶段:第一阶段为不排水、不排气阶段,土体的变形只是因为气体压缩所引起的;第二阶段为排水、排气阶段,土体的变形是因为孔隙水和孔隙气的排出而引起的.在此过程的基础上,建立并求解非饱和土一维固结方程,分析影响非饱和土一维固结的因素.影响非饱和土一维固结速率的最重要因素是孔隙流体的渗流路径.在相同边界条件下,非饱和土固结过程与饱和土固结过程中孔隙流体压力沿深度的分布随时间的变化规律相同.

Based on Bishop effective stress principle,a computation method of one-dimensional consolidation for unsaturated soil that incorporated the linear soil-water characteristic curve （SWCC） in the consolidation equation was developed.Two stages in the unsaturated soil consolidation process were assumed.At the first stage,neither water nor air is drained,and the soil deformation is only caused by air compression.At the second stage,the soil deformation is induced by the drainage of pore-water and pore-air.A one-dimensional consolidation equation system for unsaturated soil and its analytical solutions at this stage were presented.The effects of soil parameters on the one-dimensional consolidation of unsaturated soil were discussed based on the analytical solutions.The seepage path of fluid is confirmed to be the most important factor that influences the consolidation rate of unsaturated soil.The variations of pore fluid pressure with depth and time in the consolidation process of unsaturated soil are similar to those of the saturated soil with the same boundary conditions.