上海某枢纽基坑工程浅层承压水回灌试验分析

随着上海城市建设进程的不断推进,深大基坑大量涌现,同时因城市立体空间设施的密集化,使得基坑周边环境趋于复杂,在此背景下因浅层承压水降水而引起的工程性地面沉降事故不断发生,给社会带来了巨大的经济损失。地下水人工回灌是控制因降水引起的工程性地面沉降的方法之一,目前地下水人工回灌系统主要应用于深层承压水的回灌。本文通过上海某地第一承压含水层的回灌试验,研究分析了浅层承压含水层回灌井的结构、回灌过程中地下水的流态变化规律、水土应力变化及对控制地面沉降作用的效率,证明了浅层承压水回灌在基坑环境保护中的可行性。试验研究对基坑建设中的地下水浅层承压水回灌系统的设计和施工有重要的指导意义。

Test and Analysis of Artificial Recharge to the Shallow Confined Aquifer of Deep Foundation Pit in Shanghai

Land subsidence incidents caused by foundation dewatering in shallow confined aquifer occurred constantly, and it made huge economic losses to society, so the safety of foundation pit and its surrounding environment during foundation dewatering must be considered. Artificial recharge of groundwater is a method to control engineering land subsidence caused by dewatering. Artificial recharge of groundwater is mainly used in deep confined aquifer at present. This paper based on a case study in Shanghai, researched the structure of recharge well in shallow confined aquifer, variation of groundwater flow during the process of recharge, soil-water’s stress change and the efficiency to control land subsidence by groundwater recharge, to prove the feasibility of shallow confined water recharge in protection of ground environment. This paper gives an important guidance to design and construction of recharge system in shallow confined groundwater during the pit construction.