Finite Element Calculation for Large Foundation Pit Dewatering in Double-layered Aquifer Structural Foundation

摘要

For dewatering project based on multi-layered aquifer foundation which there are hydraulic relations between upper aquifer and conjoint nether one, it will influence another dynamic change of adjacent aquifer water level when dewatering in a aquifer. It is very difficult to resolve this problem according to general three-dimensional numerical method as a result of their different groundwater constitutional equation. Dewatering in phreatic water layer where there is a conjoint nether confined aquifer will increase water head difference between the two aquifers and increase leakage. The paper analyses the leakage phenomenon in east experimental field of Xuanwu Lake tunnel, predict FEM equation of foundation pit dewatering for double-layered aquifer and has a conclusion that it will be a stable phreatic water level in foundation pit when dewatering and setting up full-scale impervious curtain.