Foundation Pit Dewatering Surface Subsidence Caused By The Finite Element Analysis

The dewatering for foundation pit effects on the surroundings is firstly discussed in detail, and the bad phenomena caused by pit dewatering is emphatically analyzed in this paper. As a whole, the research work of this dissertation can be summarized as follows:The fundamental design rules ,the technique requirements and the design method are put forward in pit dewatering. The calculation formulas of radius of drawdown influence and permeability coefficient are deduced.The basic theory of the influent is relatively overall retrospect at first; then Two-Dimension unsteady seepage mathematical model is deduced, which is analysised with finite element.Based on Biot's consolidation theory by the law of conservation of mass, the principle of effective stress and the Darcy's law as well as the equilibrium differential equations , a coupled mathematic model that included the terms of source and sink , and its corresponding direct coupled FEA model for the analysis of groundwater seepage and stress were developed. The coupled characteristics of the surface settlement induced by dewatering were analyzed by the software ABAQUS.The two-dimensional FEA model was applied to the computation of a case project. The measured results compared favorably with the numerical results that verified the feasibility of the coupled model at first.Then by the two-dimensional FEA, the settlement were thought to be related with the Young's module, permeability and the depth of dewatering, etc. The settlement was analyzed in sequence at last.