一维软土地基非达西流固结分析  

One-dimensional consolidation of soft ground considering non-Darcy flows

作　　者：刘加才[1] 雷国刚 王育新[1] 

机构地区：[1]南京工业大学交通学院,江苏南京210009 [2]南京市水利建筑工程总公司,江苏南京210036

出　　处：《岩土工程学报》2011年第7期1117-1122,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50608038/E0806)

摘　　要：水在土体中的渗流规律以及边界的排水情况对土体中孔压消散的快慢有较大影响。采用Hansbo提出的可同时考虑低速渗流曲线段和较高速渗流直线段的非达西流公式模拟土中水的渗透规律,利用Galerkin加权残值方法推导了半透水边界一维非达西流固结问题的有限元方程表达式,并将其编制为应用程序。利用已有的基于达西流的双面半透水边界一维固结解析解答验证了求解方法的合理性和程序编制的正确性。在此基础上对半透水边界一维非达西流的固结特性进行了分析。分析表明,Rt=200时,半透水边界相当于完全透水边界,达西流情况孔压消散快于非达西流情况。同一时刻,半透水边界条件下达西流与非达西流固结存在一个深度分界点。分界点以上,非达西流情况孔压消散快于达西流情况;分界点以下,达西流情况孔压消散快于非达西流情况。且分界点随着m的增加而变深,但随着i1的增加而变浅。The flows of pore water in the soil and drainge boundaries have great influence on the dissipation of excess pore pressures.Based on the non-Darcy flows suggested by Hansbo described by the power function for the lower velocity of flows and the linear function for higher velocity of flows,finite element formulations are derived by Galerkin＇s weighting residual method for one-dimensional consolidation of ground with impeded boundaries.A program is developed based on the finite element formulations.The existing one-dimensional consolidation explicit analytical solution based on the Darcy flows of the ground with partially drained boundaries is used to verify the validity of the present method and correctness of the program.Then the one-dimensional consolidation behavior of ground with impeded boundaries based on the non-Darcy flows is investigated.The numerical results indicate that partially drained boundaries parameter Rt=200 can be thought as conventional pervious boundaries.There is a boundary depth for the non-Darcy flow consolidation under impeded boundaries.The pore pressures of the soil above the boundary depth dissipate more quickly than those of Darcy flows,whereas pore pressures of the soil below the boundary depth dissipate more slowly than those of Darcy flows.Boundary depth becomes deep with the increase of m,however it becomes shallow with the increase of i1.

关 键 词：一维固结 半透水边界 非达西流 有限元 

分 类 号：TU433[建筑科学—岩土工程]