软土地层深基坑悬臂式帷幕降水渗流效应研究

Study on the Seepage Effect of Dewatering for Deep Excavation with Cantilever Curtain in Soft Soil

摘要: 本文以上海地区沪通铁路太仓至四团段吴淞口长江隧道浦西接收井超深基坑工程为背景，采用ABAQUS有限元模拟软件对基坑降水渗流效应进行了研究。该基坑采用悬臂式帷幕降水方式，在承压水边界条件下，分别计算了四类降水工况，结果显示井内降水数值模拟和现场试验匹配较好，误差在可接受范围内，可为现场抽水方案的设计优化提供参考，而井外的观测井位降水数值模拟结果与实际值偏差较大。在后续的研究中，可以考虑将边界条件设置为静水压力边界对井外观测点降水进行模拟，以探究降水渗流效应对周边环境的影响。

Abstract: In this paper, ABAQUS finite element simulation software was used to study the seepage effect of dewatering for deep excavation, based on the deep excavation project for the Wu Songkou Yangtze River Tunnel on the Shanghai-Nantong Railway from Taicang to Situan in the Shanghai area. The excavation adopts the cantilever curtain method for dewatering. Under the pressure water boundary, four types of dewatering conditions were calculated. The results showed that the numerical simulation of dewatering in the well matched well with the on-site test, and the error was within an acceptable range, which could provide a reference for optimizing the design of the on-site pumping scheme. However, there was a large deviation between the simulated values and actual values of the observed wells outside the well. In future research, it is suggested to set the boundary conditions as the hydrostatic pressure boundary to simulate the dewatering of the observation wells outside the well so as to explore the effect of seepage on the surrounding environment.