以纬三路过江通道南岸工程为背景, 结合场区工程地质及水文地质条件,借鉴该地区类似工程经验,确定基坑降水的影响半径及场区综合渗透系数参考值,在此基础上进行深基坑的降水计算与设计, 详细介绍了疏干井和降压井在基坑降水中的应用。最后,建立地下水渗流数值模型,采用三维有限差分法对基坑内承压含水层降水效果进行模拟验证。模拟结果表明:该降水方案合理可行,达到了设计要求,能够取得明显的效果。实践表明降水方案合理可行,可为该地区其他类似基坑降水工程提供指导。

This research is carried out with the tunnel across Yangtze river in the south-bank at Weisan road in Nanjing as the background. In the light of the engineering geological and hydrogeological conditions in the site area, and with reference to experiences in similar projects in Nanjing, the radius of area affected by the dewatering and the comprehensive permeability coefficient of the site area were determined. On this basis, the calculation and design of dewatering for the foundation pit were carried out, and the applications of dewatering wells and buck wells in foundation pit dewatering were introduced. Furthermore, a numerical model of groundwater seepage was established to simulate and validate the dewatering effect for confined aquifer in the foundation pit by using 3-D finite difference method. The simulation results and practice both show that the dewatering scheme is reasonable and feasible.