中文摘要：

上海地下水位埋深较浅,地铁站建设大多要采取工程降水措施。以上海地铁11号线徐家汇站为例,根据场地工程地质和水文地质条件、地铁站围护结构设计深度和基坑开挖深度,建立地下水渗流数值模型,通过抽水试验反求水文地质参数,结合场地初始条件和边界条件,采用三维有限差分法对基坑降水进行模拟,数值模拟结果与地下水位实际监测数据十分吻合,同时对基坑降水引起的地面沉降进行计算,结果表明基坑周围的地面沉降能够得到有效地控制。

英文摘要：

The buried depth of groundwater level is fairly shallow in Shanghai,and pit dewatering measures are mostly adopted in construction of metro stations.This study refers to the deep foundation pit dewatering project of Xujiahui Station of Shanghai Metro Line No.11.According to the site conditions of engineering geology and hydrogeology,design depth of enclosure structure and pit excavation of metro station,a numerical model of groundwater seepage is established.Through the inversion of permeability parameters based on the field pumping tests,the three-dimensional finite difference method is used to simulate the pit dewatering considering the initial and boundary conditions.The numerical results are consistent with the actual monitoring data of groundwater level.At the same time,the land subsidence induced by dewatering is calculated.The results indicate that the land subsidence around the pit can be controlled effectively.