考虑承压含水层间越流的地下水回灌现场试验研究  

Field tests on groundwater recharge considering leakage between semiconfined aquifers

作　　者：郑刚[1,2] 曹剑然 程雪松[1,2] 哈达 ZHENG Gang;CAO Jian-ran;CHENG Xue-song;HA Da(MOE Key Laboratory of Coast Civil Structures and Safety,Tianjin 300072,China;Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学滨海土木工程结构与安全教育部重点实验室,天津300072 [2]天津大学建筑工程学院,天津300072

出　　处：《岩土工程学报》2019年第9期1609-1618,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家重点研发计划课题（2016YFC0802008）;天津市自然科学基金项目（18JCQNJC07900）

摘　　要：当场地存在多层层间有一定水力联系的承压含水层时,基坑内降水可引发基坑止水帷幕墙底以下的承压含水层的水头下降,并相应引起坑外多个含水层水位降低,若对所有层进行回灌则将导致成本大幅提高,此时可对某一层回灌,通过越流对其他含水层进行水位补给。通过在天津地铁某车站基坑所在场地开展抽水试验、单井回灌试验、先抽后灌试验对基坑内外的水力联系、不同含水层间的水力联系和隔层回灌的效果进行了研究。结果表明,由于各含水层间之间有一定水力联系导致竖向越流补给较强,基坑内疏干降水可引起坑外承压含水层水头下降并引起坑外地层沉降。对基坑外第Ⅰ微承压含水层进行回灌可有效对其上部潜水层和下部第Ⅱ-1承压层的水头起到抬升作用,通过隔层回灌从而控制其水位下降导致的坑外沉降。对第Ⅰ承压含水层进行回灌对基坑外第Ⅱ-2承压层水位抬升也有一定的作用,但是尚不足以使其因基坑内降水引起的坑外水位下降值完全恢复,建议结合设置此层的备用回灌井以控制其水位下降。The dewatering of an excavation will cause water-level drawdown in multiple aquifers outside the excavation in the presence of multiple confined aquifers where multiple hydraulic connections exist. Recharge of all layers will result in a significant increase in cost, so one layer can be recharged and the other aquifers can be recharged by leakage. The effects of dewatering tests, single-well recharge tests, and the dewatering-recharge tests on the hydraulic connections inside and outside the excavation, the hydraulic connections between different aquifers, and the effects of interlayer recharge are studied at the site of the excavation at a subway station. Due to the significant hydraulic connection between the aquifers, the vertical cross-flow recharge is strong, and the dewatering in the excavation can cause the head of the confined aquifer to fall and the subsidence outside the excavation. Recharge of the semiconfined aquifer Ⅰ outside the excavation can effectively raise the head of the upper phreatic layer and the lower aquifer Ⅱ-1, and the subsidence caused by the water-level drawdown is controlled by the interlayer recharge. For the aquifer II-2, recharge of the aquifer Ⅰ also has a certain effect on the water level, but it is still not possible to fully restore the water level. It is recommended to combine the backup recharge wells in this aquifer to control the water-level drawdown.

关 键 词：疏干降水 隔层回灌 层间越流 承压含水层 

分 类 号：TU413[建筑科学—岩土工程]