Finite Difference Numeric Simulation Of Ground Settlement Induced By Dewatering Of Foundation Pit

Ground settlement induced by dewatering of foundation pit is a 3-D coupled analysis problem of seepage and stress field . Finite difference method is adopted to solve the equation of 3-D unsteady seepage and the coupled analysis model of seepage and stress field during dewatering of foundation pit is established. Using 3-D finite-difference numeric simulation software FLAC3D and its fish language, computer codes are written and 3-D ground settlement model is established. The case of Shenyang subway dewatering is simulated and analyzed. When the designed dewatering depth is obtained the radius of dewatering scope is 50m and the ground settlement forms a quadratic function shaped slot. The depth of the slot is 50m and the maximum ground settlement at the bottom of the slot is 11.705mm. After revising model the settlement value is 12.361mm and consitent with actual settlement result. It shows the accuracy of the coupled model and computer codes. When the coupled analysis isn't considered the settlement is only 3.768 mm, so the coupled analysis must be considered. The final settlement is smaller than 15 mm and satisfies the controling settlement, so dewatering of foundation pit won't cause hazards to surrounding environment.