浅层地下水人工回灌应用于上海市工程性地面沉降防治的试验研究

Experimental Research on Artifical Recharge to Shallow Aquifer to Control Land Subsidence due to Construction in Shanghai City

上海地面沉降主要由过量开采地下水资源和大规模工程建设等因素共同影响,工程性地面沉降引起的地面沉降漏斗严重影响了周边地区生命线工程的建设及运营安全。通过开展试验研究,将深部承压含水层中应用成熟的地下水人工回灌技术引入浅部含水层中,但由于浅部含水层砂层结构及水动力条件与深部含水层差异较大,回灌工艺及方法也存在差异。本次试验工作中,改进了地下水人工回灌工艺流程,并通过同步地面形变监测分析了浅层地下水人工回灌对控制地面沉降的作用效果。结合上海地区实际地层特征以及各种回灌工艺的实际效果,评价了浅层地下水人工回灌技术在防治工程型地面沉降中推广应用的可行性及适用性。

Land subsidence in Shanghai is mainly affected by groundwater withdrawal and large-scale construction. Land subsidence occurred by large-scale construction becomes increasingly obvious with the enforcement of groundwater withdrawal management, and affects the safety of construction and working of surrounding lifeline engineering. The study of mechanism and prevention of land subsidence due to construction is low, and the pre- vention technological system hasn＇t been built. To control land subsidence occurred by construction dewatering, this paper introduces the mature technology of artificial recharge in deep confined aquifer to shallow aquifer via test study. Because the sand stratum structure and hydrodynamic condition of shallow aquifer is different with the deep one, the technics and methods of artificial recharge is also different. This test improve on the technics and methods of artificial recharge to suit the shallow aquifer, and monitoring the land surface deformation synchronously to analysis the effect of artificial recharge. To generalize the application of artificial recharge to shallow aquifer, this paper discussed the feasibility and applicability of adopting artifical recharge technology to shallow aquifer in Shanghai.