混凝土面板砂砾石坝二维有限元渗流实例分析

Case analysis on seepage flow of concrete faced sand-gravel dam by 2-D finite element

主要探索面板砂砾石坝的二维渗流计算。利用有限元方法对坝体设置竖向排水体与不设置竖向排水体两种情况下的渗流和浸润线进行研究,阐述了在坝体中设置竖向排水体能有效地控制浸润线的高度和渗流溢出点的位置,从而提高坝体下游坝坡的稳定。同时,结合面板砂砾石坝的渗流分析,对面板砂砾石坝的设计提出了建议,指出:当面板无裂缝,面板与防浪墙之间的水平缝止水失效时,即使在设置竖向排水体的情况下,浸润线仍保持一个较高的位置,对坝坡稳定有较大的不利影响,在设计和施工时应予足够重视。

We introduce 2 - D seepage calculation （ seepage flow and saturation line） of concrete faced sand - gravel dam. We study the seepage and saturation line with and without a vertical drainage body by 2 - D finite element. The analysis results show that the vertical drainage body in dam can effectively control the height of saturation line and location of outflow point of seepage and improve the stability of downstream dam slope. According to the seepage analysis result, the suggestions on the design of concrete faced sand - gravel dam are put forward and it is pointed out that when no crack exists and water - stop in horizontal joint between concrete face and wave - wall fails, even if the vertical drainage body is constructed, the saturation line is still in a high elevation, which destroys the stability of the dam body. This problem should be paid attention to in design and construction.