Pumping Test Analysis and Dewatering Design Based on Numerical Simulation

为降低深基坑工程的设计与施工风险有必要通过抽水试验确定各地层(特别是承压含水层)的水文地质参数。针对上海某地铁站，通过现场抽水试验确定基坑开挖影响深度范围内地下水的分布特征和抽水影响半径等参数，应用数值模拟的方法对实测水位进行反演，获得了各含水层的水文地质参数；最后应用反演后的数值模型，对基坑工程进行了降水设计，并预测了基坑安全水位降深下基坑外承压水的分布特征及降水引起的地面沉降。In order to reduce the design and construction risks of the deep foundation pit project, it is necessary to determine the hydrogeological parameters of each layer (especially the confined aquifer) through pumping tests. For a subway station in Shanghai, the distribution characteristics of groundwater within the depth of the foundation pit excavation and the influence radius of the well were determined through the on-site pumping tests. The numerical simulation method was used to inverse the measured water level, and the hydrogeological parameters of each aquifer were obtained. Finally, the dewatering plan of the excavation pit was determined the by the inversion numerical model. And the groundwater drawdown and ground settlement induced by dewatering were predicted.