苏州地区基坑微承压水特征及其工程控制技术研究

苏州地铁4号线附属结构及出入口基坑开挖深度为10 m左右。基坑底一般坐落于微承压含水层中,由于开挖深度较浅,第一承压含水层对基坑无突涌威胁。对基坑开挖有直接影响的主要为潜水和微承压含水层。通过苏州地铁深基坑工程实践,分析总结归纳了苏州地区微承压水的特征,并采用有限元方法预测分析了降微承压水对周边环境的影响规律。在此基础上,总结提出了苏州地区基坑地下微承压水层对环境影响的控制技术。

Features of Feeble Confined Water and Controlling Technologies in Suzhou Area

The excavation depth of the subsidiary structure and entrance is about 10 m on Suzhou metro Line 4,the bottom of the foundation pit is generally located in the feeble confined water layer.Due to the shallow depth of excavation,the first confined aquifer suffers no sudden surge threat to the pit,and the impact on excavation is mainly coming from the unconfined aquifer and feeble confined aquifer.Based on the practice of Suzhou metro excavation,the features of the feeble confined water in Suzhou area are systematically analysed,the finite element method is used to prodict and analyze the environmental impact caused by dewatering the feeble confined water.On this basis,countermeasures to control the influences of dewatering groundwater (feeble confined water)in Suzhou area are summarized.