水布垭大坝左岸岩溶发育规律及渗透性分析

利用水布垭大坝左岸山体灌浆平硐现场的调查结果,对防渗帷幕线剖面不同高程灌浆平硐的面溶蚀率和最大溶蚀洞径进行分区统计分析,获得了防渗帷幕线剖面岩体溶蚀特性．在此基础上,结合区域地质资料和地貌资料,得出大坝左岸山体岩溶发育规律．左岸山体岩溶发育在垂直方向从上到下逐渐减弱,水平方向从远河岸端向近河岸端逐渐增强,存在集中发育区并受岩层面控制等．最后对山体的渗透性进行了探讨,提出帷幕工程优化的初步建议。对大型溶蚀洞穴系统进行封堵后,帷幕灌浆时应对不同地区分别对待,有些地带可以简化帷幕施工,甚至可以不进行帷幕施工。

Regularity of karst growth on the left bank of Shuibuya Dam and its permeability analysis

Based on the field investigation of grouting tunnels in the mountain on the left bank of the Shuibuya Dam, a sectional statistical analysis is performed on the areal corrosion ratio of grouting tunnels at different elevations of the curtain line section and the maximal diameter of solution caves, and the corrosion characteristics of rocks in the section of impervious curtain line are obtained. In combination with the local geological and geomorphological data, the regularity of karst growth of rocks on the left bank of the dam is found out. It is concluded that the karst growth weakens from up to down in the vertical direction, and gradually strengthens from off-shore areas to near-shore areas in the horizontal direction, and that there exist centralized growth regions, which are controlled by rock strata. Finally, a discussion is made on the permeability of the mountain, and some suggestions on optimization of the curtain grouting project are made: for large solution caves after sealing, different curtain grouting measures should be taken in different areas; in some areas, simplified curtain grouting could be adopted, or there is not any curtain construction needed.