Research on Dewatering Design of PumpingTest in Super Large Foundation Pit Engineering -Taking the Foundation Pit in J2 Area of Nanjing QingaoTunnel as an Example

The purpose of this paper is to determine the water level of the confined aquifer and the water output of a single well, to test the well completion quality of the dewatering well, to determine the permeability coefficient of the confined aquifer, and to test whether the parameters selected in the design of the dewatering scheme are reasonable, etc. The constant flow and steady flow pumping test method is mainly used to analyze and compare the pumping test data of the belt observation logging in Nanjing Qingao tunnel project, The analysis of the pumping test results of this type and the correct selection of the permeability coefficient formula provide a good example for the foundation pit dewatering design to be more detailed and reasonable.