深基坑嵌岩地下连续墙隔渗效果分析与评价方法研究

Analysis and evaluation of sealing effect of rock-socketed underground diaphragm in deep foundation pit

嵌岩地下连续墙上渗漏点位置、大小等的不确定性,使数值模拟预报该状况下基坑内降水后地下水的流场十分困难。结合对武汉地铁2号线循礼门地铁车站嵌岩地下连续墙的实际隔渗效果分析,在数值模拟计算时提出了"纵向平移集中法"处置防渗墙渗漏点的方法;采用该方法的三维数值计算结果与实测结果基本吻合,证明该处置方法可用于模拟及预报存在渗漏的防渗墙内基坑降水的地下水流场变化过程,为解决该工况下渗流场的模拟计算问题提供一种途径;同时还分析、探讨了嵌岩地下连续墙的实际隔渗效果。该工程实例中的分析方法对同类工程具有借鉴作用。

When dewatering in deep foundation pit, the uncertainty of the leakage point location, size, and so on in the rock-socketed underground diaphragm in deep foundation pit cause the numerical simulation and prediction of the groundwater flow field very difficult to handle. Based on the analysis of the sealing effect of the rock-socketed underground diaphragm in Xunlimen station of Wuhan subway line No. 2, a method of longitudinal translation and put together is used to deal with the leak point in diaphragm while numerical simulation calculating. The results through 3D numerical simulation by this method are very close to the results obtained from actual measurement, it shows the possibility of using the method to deal with the problems of simulation and prediction of change process of the groundwater flow field in the case of dewatering in the rock-socketed underground diaphragm while it exists leakage point; it provides an approach to solve the problem. In the meantime, the actual sealing effect of the rock-socketed underground diaphragm is analyzed and discussed. The analytical procedure discussed for the project instance can be used for reference to the similar engineerings.