软土地区地铁基坑浅层承压水控制及降压影响预测研究

针对地铁基坑,提出一种浅层承压水抽灌一体化设计理念,用以控制因地下水位下降引起的被保护建(构)筑物的环境变形。结合宁波市轨道交通工程实例,分析地铁基坑浅层承压水抽灌一体化设计在实际工程应用中的优势,通过现场试验,证明抽灌一体化的设计方法可有效减小基坑降压引起的周边地面沉降。同时对该地铁站进行数值模拟计算,得到抽灌一体化设计下的环境水位变化。通过理论推导,结合工程实测数据和数值计算结果,提出适用于宁波地区的减压降水引起的地面沉降预测公式。

Control of Confined Water and the Calculation of the Effect of Falling Groundwater Levels of a Subway Foundation Pit in Soft Soil

To control the environmental deformation of buildings due to falling groundwater levels in the construction of a subway foundation pit, a pumping-recharge integration design was advanced. In addition, an analysis of the advantage of pumping-recharge integration design in engineering application is undertaken based on a subway station in Ningbo. It was demonstrated that the pumping-recharge integration design can effectively reduce the environmental deformation of buildings caused by water pressure reduction of the foundation pit, based on field tests. The results of the environmental water levels are then obtained based on numerical calculations. Finally, using theoretical deduction and the results of engineering measurement and numerical calculations, the formula for calculating the land subsidence caused by falling groundwater levels is presented. These findings are applicable?to the?Ningbo area.