考虑非饱和区变形的基坑降水沉降分析  

Sedimentation Analysis of Deformed Foundation Pit Dewatering in Saturated-unsaturated Zone

作　　者：许芃[1] 裴向军[1] 刘果果[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：《成都大学学报（自然科学版）》2015年第4期412-416,共5页Journal of Chengdu University（Natural Science Edition）

摘　　要：传统的基坑降水渗流沉降耦合分析中,通常未考虑非饱和区的变形以及土体的非线性特征.本研究基于非饱和土有效应力理论,考虑土体孔隙特征及渗透性随应力状态的动态变化,建立了基坑降水饱和—非饱和渗流沉降耦合模型.利用Flex PDE软件编制计算程序,对一典型基坑降水模型进行了计算分析.分析结果表明,渗流—变形耦合效应会对地下水渗流场的分布造成一定影响,而孔隙度、饱和渗透系数变化对地面沉降的影响则具有时间效应;基坑降水初期,地面沉降速度较快,降水中应该引起格外重视.In the traditional coupled analysis of seepage sedimentation of foundation pit dewatering,the deformation in unsaturated zone as well as the nonlinear characteristics of the soil are always ignored.Based on the effective stress theory of unsaturated soil and considering the dynamic changes of porosity and permeability with the stress state,a coupling model of seepage sedimentation of foundation pit dewatering in saturated-unsaturated soil is established. Based on the Flex PDE software,a typical foundation pit dewatering model is calculated and analyzed. The results show that the coupling effects of seepage and deformation will cause a certain influence on the seepage of groundwater,while the variation of porosity and saturated permeability coefficient has time effects on ground settlement. At the early stage of foundation pit dewatering,ground settles faster and special attention should be paid to it.

关 键 词：基坑降水 饱和—非饱和 流固耦合 浸润线 地面沉降 

分 类 号：TU463[建筑科学—结构工程] TU433[建筑科学—土工工程]