半无限平面内非饱和土降雨入渗的水—力耦合数值分析  

Hydro-mechanical Coupling Numerical Analysis of Semiinfinite Unsaturated Soil Rainfall Infiltration

作　　者：石伦炎 吴礼舟[1] 周杨[1] 白兰英[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《水电能源科学》2017年第3期134-137,126,共5页Water Resources and Power

基　　金：国家自然科学基金项目(41172280;41272005);四川省杰出青年技术带头人计划项目(2012JQ0007);四川省教育创新团队项目

摘　　要：降雨入渗是非饱和土中水分迁移的重要因素。通过VG模型、渗流理论和弹性力学理论,推导出二维非饱土水—力耦合控制方程,利用COMSOL Multiphysics有限元软件对非饱和土渗流变形耦合控制方程组进行计算,研究了不同模型尺寸下土体中压力水头随时间的演化及变化规律,采用数值方法探索半无限非饱和土降雨入渗问题。结果表明,半无限渗流问题在一定条件下可作为有限尺寸的渗流问题;降雨入渗过程中水头水平向变化比竖向大;压力水头在非耦合情况下比耦合情况下入渗更快,但两者的压力水头分布无明显差异;降雨初期顶点位移就发生明显的变化。The moisture migration in unsaturated soil was mainly caused by rainfall infiltration.Based on VG model,seepage theory and elasticity theory,two-dimensional hydro-mechanical model in unsaturated soils was established.The unsaturated coupled seepage-deformation equations were solved by using the finite element software COMSOL Multiphysics.The characteristics and changes of the pressure head were discussed based on different sizes of the soil model and the problem of semi-infinite unsaturated soil rainfall infiltration was explored according to the numerical results.The results show that semi-infinite seepage problems can be studied as finite-size seepage problems under certain conditions.During rainfall infiltration the lateral predication of pressure head is larger than the vertical.The pressure head changed faster under uncoupled conditions than that under coupling conditions,and the distribution of pressure head has no significant difference.The top displacement changed obviously with initial rain.

关 键 词：降雨入渗 非饱和土 数值分析 半无限 水—力耦合 

分 类 号：TU46[建筑科学—结构工程]