摘要
控制地下水对基坑开挖和周围环境的负面影响,是基坑工程特别是深基坑工程设计与施工的重要组成部分.采用三维有限元法分析了基坑渗流场的分布特性,比较了不同土质条件下渗流作用对基坑土体渗透稳定性的影响,较好地反映了基坑渗流场中等势线、流速矢量以及水力梯度等渗流要素在不同土质条件下的变化规律,探讨了工程中可能出现的不利因素.分析表明,在均质各向同性非成层土中,基坑角点和溢出点附近水力梯度最大,是整个基坑最易发生渗透破坏的地方;在成层土情况下,水头等势线有向渗透系数小的土层聚集的趋势.对比各种分析结果,当水平向渗透系数大于竖向渗透系数时,基坑最容易发生渗透破坏.
To reduce the negative influence of the groundwater upon foundation pit excavation and surrounding environment, analysis of seepage field becomes very important in deep excavation projects. A series of three-dimensional finite element method are conducted in this paper to analyze the seepage field characteristics in foundation pits. Then the influence of seepage field on soil stabilization under different soil property conditions were studied, Variation laws of main physical quantities, such as contours of pressure head, flow vector and hydraulic gradient, with different soil properties in foundation pit excavation were presented. Some disadvantageous aspects probably appearing in the project were discussed. The analysis shows that contours of pressure head have the tendency to gather towards soil with lower permeability coefficient and maximum value of hydraulic gradient in isotropic unstratified soil occurs between angular point and spillpoint where seepage failure occurs easily. The analysis results also show that foundation pit tends to fail in anisotropic soil when horizontal permeability coefficient is larger than that of vertical.
出处
《天津大学学报》
EI
CAS
CSCD
北大核心
2006年第11期1299-1304,共6页
Journal of Tianjin University(Science and Technology)
关键词
基坑
土质
渗流场
有限元法
foundation pit
soil properties
seepage field
finite element method
