深基坑减压降水引发的地面沉降效应分析

Analysis of the Land Subsidence Impact of Dewatering of Deep Foundation Pits

上海地面沉降近年呈现出不均匀性特征,深基坑减压降水等工程活动是其主要原因之一。根据某地铁车站深基坑工程减压降水和地质环境监测结果,分析了深基坑工程的地面沉降效应。研究表明,减压降水是导致基坑周边地面沉降的主要因素,浅层地下水回灌可作为地面沉降控制的有效措施,而基坑围护与工程降水一体化设计是未来工程性地面沉降防治的重要方向。该研究成果可为工程性地面沉降防治提供科学依据和实践指导。

Land subsidence in Shanghai has in recent years undergone a significant change, with the development of significant amounts of uneven settlement; one of the main reasons for this uneven settlement is the dewatering of deep foundation pits. Here, we present results obtained during the excavation of foundation pits for a subway station combined with dewatering and geological environment monitoring, and discuss the impact of land subsidence induced by dewatering of foundation pits. We suggest that that dewatering is the main cause of land subsidence, and groundwater recharge in shallow aquifers can effectively control land subsidence. It is apparent that integration of foundation pit bracing design and dewatering engineering will become increasingly commonplace as engineering tools to prevent land subsidence. This paper provides a scientific basis for, and indicates the real value of, prevention and control of engineering land subsidence.