试验研究 2026年 第卷 第04期

DOI: 10.7672 / sgjs2026040152

上海软土深基坑承压水抽水⁃回灌试验分析

杨光辉¹,胡世亮¹,李泽文²

作者简介:

杨光辉,高级工程师,E⁃mail: yanggh44@ 163. com

作者单位:

1.上海城建市政工程(集团)有限公司,上海 200032; 2.同济大学土木工程学院,上海 200092

摘要:

软土地层易受施工扰动,基坑降水设计不当会严重影响周边环境。以上海某在建车站深基坑工程为例,通过现场抽水和回灌试验,研究了降水对周边地层沉降的影响规律,并基于回灌试验结果,提出相应的措施。试验结果表明,尽管各层承压水水位补给较慢,但在减压降水阶段仍不可长时间停止抽水;抽降承压水引起的地面沉降呈以抽水井为中心的辐射状漏斗形态,深层沉降主要集中于第⑧2 层承压含水层,占总沉降约 44.8%;停止抽水后,地层沉降随水位恢复出现一定滞后性回弹。为保护基坑周边敏感建筑物,建议采取延长绕流路径与布设应急回灌井等综合措施,控制坑内减压降水对坑外水位的影响。

English:

Soft soil strata are susceptible to construction disturbances, and improper design of foundationexcavation dewatering can severely affect the surrounding environment. Taking the deep foundationexcavation project of a station under construction in Shanghai as an example, through on⁃site pumpingand recharge tests, the impact of dewatering on the settlement of the surrounding strata was studied, andcorresponding measures were proposed based on the results of the recharge tests. The test results showedthat although the recharge of confined aquifer levels in each layer was relatively slow, pumping should notbe stopped for a long time during the decompression dewatering stage. The ground settlement caused bypumping and lowering confined aquifer exhibited a radial funnel shape centered around the pumping well,with deep⁃layer settlement mainly concentrated in the ⑧2confined aquifer, accounting for about 44.8%of the total settlement. After stopping pumping, the strata settlement showed a certain lag in rebound withthe recovery of water levels. To protect sensitive buildings around the foundation excavation, it isrecommended to adopt comprehensive measures such as extending the bypass path and arrangingemergency recharge wells to control the impact of decompression dewatering inside the pit on the waterlevels outside the pit.