金河四级水电站左岸坝基渗漏分析与防渗处理

Analysis of left bank dam foundation and seepage treatment for Jinhe-4 hydropower project

左岸坝肩为坚硬的熔结火山角砾岩，但距坝体50m处发育一条Ⅲ级结构面（F5断层），坡脚出露软弱的强风化云煌岩，故造成此带岩体卸荷强烈，且发育一组顺河向的节理，延伸长、张开、无充填，是绕坝渗漏的主要通道。施工中未做好帷幕灌浆，水库试蓄水后，渗漏严重，经二次帷幕灌浆工程处理后，已无渗漏，边坡稳定性好。

Rock formation at left abutment is volcanic breccia, but a structural plane （fault F5） of grade Ⅲ is developed 50m away from dam and heavy weathering is outcropped at hill foot, causing strongly load relieved rockmass and a long, open joint group. As curtain grouting is not well done in construction, after impounding, percolation is found serious. After secondary grouting, no seepage is found and side slope is stable.