Numerical modeling of foundation pit dewatering based on Visual Modflow

Abstract

After the investigation of a foundation pit project and the preliminary determination of the precipitation design scheme, the distribution of water level drawdown and land subsidence in the whole site was simulated by Visual Modflow software. The simulation results show that by setting the pump output of the 14 confined dewatering wells in the pit varying from 70 ~ 420 m3/day, the drawdown of the foundation pit can be uniformly reduced to about 4m. Due to the waterproof curtain, the waterline distribution inside the foundation pit is relatively uniform, which proves the rationality of the setting of the pumping well. At the same time, the waterline contour around the edge of the curtain is very intensive, indicating that there is huge difference in the drawdown between inside and outside of the waterproof curtain. The curtain plays an effective role in controlling the drawdown inside and outside the pit foundation, hence, the compression deformation and settlement of the soil are also small so as to avoid the damage of the surrounding buildings due to the uneven settlement of the ground surface. Therefore, the precipitation design has achieved a good effect.