临江强透水地层止水帷幕有效性对基坑渗流特性的影响分析  

Analysis of the Influence of the Effectiveness of Waterproof Curtain on the Seepage Characteristics of the Foundation Pit in the Strong Permeable Stratum near the River

作　　者：李伟科 彭学忠 黄俊光 黄少鹏 毕俊伟 李磊 LI Weike;PENG Xuezhong;HUANG Junguang;HUANG Shaopeng;BI Junwei;LI Lei(Guangzhou Design Institute Group Co.,Ltd.Guangzhou 510620,China;Guangzhou Construction Co.,Ltd.Guangzhou 510030,China;Guangzhou Port Group Co.,Ltd.Guangzhou 510100,China)

机构地区：[1]广州市设计院集团有限公司,广州510620 [2]广州建筑股份有限公司,广州510030 [3]广州港集团有限公司,广州510100

出　　处：《广东土木与建筑》2023年第6期9-12,104,共5页Guangdong Architecture Civil Engineering

基　　金：广州港集团有限公司技术研发项目(20210150);广州市建筑集团有限公司科技计划项目(2021-KJ006)。

摘　　要：为研究止水帷幕失效条件下临岸基坑的渗流特性,以广州某临岸基坑工程为背景,基于饱和非饱和土体非稳定渗流基本方程,建立三维有限元数值模型,从渗流路径、等势线分布、渗透坡降等方面分析了止水帷幕部分失效和完全失效条件下的基坑渗流特性。结果表明:止水帷幕未失效时,基坑内部无连续渗流通道,水流在止水帷幕外侧发生绕流偏转。止水帷幕部分失效条件下基坑的渗流路径与完全失效时类似,基坑渗流路径主要受透水层和墙下绕渗的影响。止水帷幕部分失效或完全失效时,等势线分布趋势类似,均较为均匀。止水措施未失效时基坑渗流量为4.031m^(3)/d,考虑止水帷幕部分失效和完全失效条件下,基坑渗流量分别为73.699m^(3)/d和81.994m^(3)/d。止水帷幕部分失效条件下基坑渗流特性与完全失效相差较小,且渗流量主要取决于地基透水土层止水帷幕的有效性。In order to study the seepage characteristics for the near-shore foundation pit under the failure condition of waterproof curtain,according to the basic equations of unsteady seepage for the saturated and unsaturated soil,3D FEM models were built based on one nearshore foundation pit in Guangzhou.Considering partial and complete failure conditions of the waterproof curtain,the seepage path,iso-potential line distribution,and seepage slope are discussed in detail.Results show that,when the waterproof curtain works well,there is no continuous seepage path in the foundation,and the water deflected around outside the waterproof curtain.The seepage paths under the partial failure condition of the waterproof curtain are similar to those when the waterproof curtain fails completely,indicating that the seepage path are mainly effected by the permeable stratum and the by-pass seepage around curtain.The iso-potential line distributes uniformly when the waterproof curtain fails partially,which is similar to that under the complete failure condition of the waterproof curtain.When the waterproof curtain was not failed,the seepage flow rate for the foundation pit is 4.031 m^(3)/d.Considering partial and complete failure conditions of the waterproof curtain,the seepage flow rate is 73.699 m^(3)/d and 81.994 m^(3)/d respectively.Additionally,the seepage characteristics for the nearshore foundation pit under partial failure condition of waterproof curtain are similar to those when the curtain fails completely.The seepage flow of the foundation pit mainly depends on the effectiveness of the waterproof curtain for the permeable soil stratum.

关 键 词：止水帷幕 临岸基坑 渗流路径 等势线 渗透坡降 

分 类 号：TU398.9[建筑科学—结构工程]