三峡大坝基础渗流控制措施效果分析

Analysis on Effects of TGP Dam Foundation’s Seepage Control System

通过对三峡大坝左＃９～右＃２１坝段基础渗流场的有限元数值模拟，对比分析了排水孔幕的孔距、建基面的高程以及封闭和不封闭防渗排水的型式对渗流控制效果的影响，并采用接近实际的设计排水孔距，用三维模型模拟分析了防渗排水系统的渗控效果。研究结果表明，虽然渗透剖面图显示坝基岩体的渗透性很小，但帷幕结合排水孔的防渗排水措施仍是必要的，此设计方案具有较好的渗控效果。

By means of FEM numerical simulation of the seepage field in the TGP dam foundation at the dam sections from left No.9 to right No.21, the influences of the drain hole intervals, the elevation of the dam foundation and seepage drain control system of close type and open type on the seepage control effects are comparatively analyzed. Using 3 D model with near practical drainage hole intervals, the seepage control effect is further simulated. The results show that, although the permeability of foundation rock is low, the seepage control system of grout screen along with drainage holes still works well.