膜土联合防渗系统对高土石坝心墙拱效应的影响

以四川瀑布沟心墙土石坝为例,应用FLAC3D软件建立高土石坝的三维模型并对高土石坝的应力应变和渗流进行了数值模拟,同时将此数值模拟结果与其他文献中的计算结果进行了对比.结果表明:高土石坝中心墙处会出现拱效应现象;土工膜与土心墙组成的联合防渗系统可大大降低心墙浸润面,有效削弱心墙拱效应,完全消除心墙大主应力小于同高程渗透水压力的现象,从而提高防渗心墙的安全性.

Effect of geomembrane and core-wall united impervious system on arch effect of core-wall in high earth-rock dams

With Pubugou core-wall earth-rock dam in Sichuan Province as an example,a 3D model for the high earth-rock dam was developed by using FLAC3D software,and the stress,strain,and seepage of the earth-rock dam were simulated.The comparison of the simulated result with those from other references shows that arch effect might occur in the core-wall of the high earth-rock dam.The united impervious system of geomembrane and core-wall can greatly lower the phreatic surface in the core-wall,weaken its arch effect,and completely eliminate the phenomenon that the major principal stress of the core-wall is smaller than the seepage water pressure at the same elevation,so that the safety of the impervious core-wall could be improved.