西南某水电站断裂构造和层间溶蚀带组合岩溶渗漏研究  

Study on karst leakage caused by the combination of fault structure and interlayer corrosion zone of a hydropower station in southwest China

作　　者：冯志刚 韦国建 张汉猛 许国 FENG Zhigang;WEI Guojian;ZHANG Hanmeng;XU Guo(Nanning Survey and Design Institute Group Co.,Ltd.,Nanning,Guangxi 530022,China;Nanning Research Center of Big Data Engineering Technology in Shallow Geology,Nanning,Guangxi 530022,China;China Energy Engineering Group Guangxi Electric Power Design Institute Co.,Ltd.,Nanning,Guangxi,530007,China)

机构地区：[1]南宁市勘测设计院集团有限公司,广西南宁530022 [2]南宁市浅表地质大数据工程技术研究中心,广西南宁530022 [3]中国能源建设集团广西电力设计研究院有限公司,广西南宁530007

出　　处：《中国岩溶》2022年第5期728-735,共8页Carsologica Sinica

基　　金：南宁市科学研究与技术开发计划项目(ZC20211003);南宁市创新创业领军人才“邕江计划”资助项目(2020016)。

摘　　要：西南某水电站坝址基岩为碳酸盐岩,坝区断层构造和岩溶较发育。水库蓄水后,坝址右岸抗力体1315m排水洞出现持续渗漏。随库区水位升高,涌水量逐渐加大至约1.9m^(3)·s^(-1)水库无法正常蓄水。为查明库水渗漏途径,有针对性地采取措施减少渗漏量,开展了岩溶渗漏研究。通过工程地质测绘、岩溶水文地质调查、钻探、压水试验、孔内电视、孔内电磁波CT等勘察手段,结合前期平硐、基坑开挖和物探等勘查成果,并利用灌浆孔灌浆过程试验数据,最终查明库水渗漏通道:在水压力作用下,库水沿断裂构造F_(12)下渗,在深部沿层间溶蚀带绕过防渗帷幕,呈30°倾角向下游逐步抬升,最终通过竖向岩溶发育带,从1315 m排水洞地质薄弱点涌出。通过对灌浆帷幕采取补强措施,封堵了主要渗漏通道,库水渗漏得到有效控制,达到了设计要求。A hydropower station in southwest China is located in the middle part of the fold belt between the eastern Yunnan platform and the western Guizhou platform on the Yangzi platform. The largest fault in the near field area is F38, which is 61 km long and generally protrudes to the northwest in an arc shape. The dam site is located in the eastwest structural belt on the south side of F38 fault, which is the core area of the northeast end of Dashuitang oblique anticline with an axial direction of NNE. At the dam site, the river flow direction is 25°-30°, and the valley is basically in symmetrical V shape. The dam area is dominated by carbonate rocks, and faults and karst are relatively developed.There are karst funnels, depressions, sinkholes and other surface karst forms in the upper level of planation surface on both sides of the dam site. Early investigation results of adits, drilling, foundation pit excavation and geophysical prospecting show that there are some karst caves, trough-like caves and interlayer corrosion in the riverbed and both sides, which are interconnected according to their extension trend. Since the reservoir starts to store water, continuous leakage has occurred in the 1,315 m drainage tunnel of the resistance body on the right bank of the dam site. With a rapid rise of the reservoir water level, a large number of muddy fillings gush out from each water inflow point. Then the water gradually becomes clear, the leakage gradually increases to about 1.9 m^(3)·s, and the reservoir cannot store water normally. In order to find out the leakage path of reservoir water and take measures to reduce leakage, karst leakage research is carried out. 15 boreholes are arranged on the right bank of the dam site, with the borehole bottom elevation from 1,133.3 m to 1,249.9 m, and the borehole water pressure tests of 121 section are carried out below the bottom elevation of the dam foundation curtain. Results show that the permeability area of Lugeon value q≥3 Lu below the curtain bottom elevation is distri

关 键 词：岩溶 断裂构造 溶蚀带 补强灌浆 碳酸盐岩 渗漏 

分 类 号：TV738[水利工程—水利水电工程] P642.25[天文地球—工程地质学]