乌东德水电站左岸进水口边坡岩溶问题分析

Analysis on karst phenomena in left bank intake slope of Wudongde hydropower station

乌东德水电站左岸地下电站进水口边坡下游侧与大坝及缆机平台边坡、坝肩边坡相接。在边坡开挖支护过程中揭露到溶洞(缝),导致锚索施工困难,从而引起了各方对溶洞(缝)、溶蚀洼地、强风化角砾岩等岩溶现象可能影响到边坡整体稳定性的担忧。通过研究,溶蚀洼地第四系堆积体外侧为巨厚的Ⅲ1～Ⅲ2级岩体,强风化角砾岩呈囊状发育,周围亦被巨厚的Ⅲ1～Ⅲ2级岩体阻隔,均不影响边坡的整体稳定;坡表与锚索孔揭露的溶洞(缝)未形成连通管道,且溶缝与边坡走向大角度相交,亦不影响边坡的整体稳定。相关成果对边坡岩溶研究方法和类似工程的工程处理措施具有借鉴意义。

The downstream side of the left bank intake slope of the underground powerhouse of Wudongde hydropower station is connected with the dam,the cable machine platform slope and the dam abutment slope.The Karst Cave (seam)exposed in the slope excavation and support resulted in difficulties in the construction of the anchor cables.Karst phenomena such as Karst Cave (seam),uvala,the severely weathered breccia may affect the overall stability of the slope.According to the research,the outside of Quaternary accumulation body of the uvala is blocked by very thick Ⅲ1~Ⅲ2 rock mass,and the severely weathered breccia is developed as saccule and also blocked by very thick Ⅲ1~Ⅲ2 rock mass,so they all do not affect the overall stability of the slope.The slope surface and the karst cave exposed by the anchor cable hole drilling do not connect,and the Karst seam and the slope direction intersects with large angle,so,the overall stability of the slope does not been effected.The method of slope karst research and engineering treatment introduced in this paper are of reference significance to similar projects.