面板砂砾石坝异常渗流及破坏机制探讨

利用非饱和土渗流理论,对沟后面板砂砾石坝进行了三维渗流场分析.通过渗流计算表明:渗注场受面板纵向缝止水失效的影响不大,仅仅呈现垂直人渗的特征.面板顶部与防浪墙接缝止水失效单独作用时仅能饱和坝体顶部小范围土体.面板在一定范围与坝体脱开、坝体填料渗流性质各向异性、库水位漫过防浪墙底板,这些异常情况的组合导致了坝体渗透破坏.异常状态渗流发生时,坝体顶部区域饱和,而坝体中部仍存在非饱和区,坝体下部饱和区相应点处孔隙水压力值则无明显提高.

Research on abnormal seepage and failure mechanism of faced rockfill dam

The 3D seepage analyses of Gouhou faced rocldill dam was conducted using unsaturated soil seepage theory.The conclusions are that:the watertight invalidation of longitudinal joint would not affect much on the seepage field of the dam and it would only lead to a vertical direction seepage.The crack between the slab and the wave wall would only saturate a small scale soil nearby.combination of several abnormal cases including the separation betweenthe slab and dam,the hydraulic anisotropy of dam material and the water level over the bottom of the wave wall leads to the seepage failure of the dam.When the abnormal seepage happens,the unsaturated zone still exists in middle part of the dam,while the value of pore pressure in the saturated zone of the bottom dam does not increase obviously.