上海地区承压含水层回灌试验研究

上海地区深大基坑越来越多,且承压含水层的厚度大,止水帷幕难以完全截断承压含水层,多采用悬挂式止水帷幕,势必对周边环境影响大。目前,采用回灌措施控制降水引起沉降的理念越来越受重视,但理论尚缺乏研究,回灌的可行性、关键技术也亟需研究。结合上海市首条市域铁路工程,开展了一系列单井回灌、抽灌一体化试验以及群井回灌试验。试验结果表明,在粉砂为主的土层中进行回灌是可行的;效果与回灌井间距、滤管长度、加压与否以及施加压力大小等因素有关。

Experimental Study on Recharge of Confined Aquifer in Shanghai Area

There are more and more large deep foundation pits in Shanghai,and the confined aquifer is thick.It is difficult for the waterproof curtain to completely cut off the confined aquifer.It is bound to have a great impact on the surrounding environment if suspended waterproof curtain is often used.At present,more and more attention has been paid to the concept of using the recharge measures to control pumping induced settlement,but the theory is still lack of research,and the feasibility and key technology of recharge also need to be studied.Based on the first city railway project in Shanghai,a series of tests of single well recharge,pumping recharge integration and group well recharge are carried out.The test results show that it is feasible to carry out recharge in the silt layer,and the effect is related to such factors as the spacing of recharge wells,the length of filter pipe,the pressure or not and the magnitude of applied pressure.