岩溶水库渗透破坏型渗漏勘察与评价  

Investigation and evaluation of the leakage caused by seepage failure in karst reservoir

作　　者：曾荣福 郑克勋 王钦权 ZENG Rongfu;ZHENG Kexun;WANG Qinquan(Power China Guiyang Survey and Design Corporation Limited,Guiyang,Guizhou 550081,China;Geotechnical Engineering Corporation Limited,Sinohydro Guiyang Survey and Design Corporation Limited,Guiyang,Guizhou 550081,China)

机构地区：[1]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081 [2]中国水电顾问集团贵阳勘测设计研究院岩土工程有限公司,贵州贵阳550081

出　　处：《中国岩溶》2023年第1期119-127,共9页Carsologica Sinica

摘　　要：以重庆市南川区肖家沟水库蓄水多年之后库首右岸发生的岩溶渗漏为例,探讨了岩溶水库长期运行过程中防渗体系因高压渗透破坏产生的岩溶渗漏的勘察与评价方法。通过地质分析、渗漏历史调查、钻孔、水文地质测试、物探及连通试验等方法,查明了水库右岸岩溶渗漏的范围及原因。水库渗漏边界清晰,渗漏范围主要是右岸可溶岩区的630 m高程以上,防渗体渗透破坏是水库产生渗漏主要原因。其渗漏途径一是沿原封堵堵头的薄弱区域或溶洞封堵体周边发生渗透破坏产生新的通道向下游溶洞出口集中的渗出,二是穿过右岸防渗线绕过右岸坝肩后沿岩体溶蚀裂隙或管道汇入下游右岸岸坡溶洞集中的渗出地表。通过此工程实例,提出了岩溶水库防渗体渗透破坏型渗漏的勘察与评价方法,宜以历史资料分析为基础,初判渗漏成因及范围,采用勘探、试验及物探等多种手段进行验证,为防渗处理提供可靠依据。The karst leakage that occurred after the impoundment on the right bank of Xiaojiagou Reservoir in Nanchuan district of Chongqing has been taken as an example in the investigation and evaluation of karst leakage caused by high-pressure infiltration of the anti-seepage system during the long-term operation of karst reservoir.By means of geological analysis,historical investigation of leakage,drilling,hydrogeological test,geophysical prospecting and connectivity test,the range and causes of karst leakage on the right bank of the reservoir have been identified.According to the geological analysis,groundwater level observation and water permeability characteristics,the dam area is composed of karst rock,where dissolution occurs and fracture develops,and the local water permeability rate is large,hence there exist basic conditions for leakage.Besides,the limited groundwater recharge near the dam site and the low and flat groundwater level under the influence of limestone karst contribute to the hydrodynamic conditions for leakage.Combined with the analysis of temperature field,conductivity field and chemical field of reservoir and leakage point,the areas of abnormal groundwater temperature and conductivity on the right bank are mainly concentrated near the groundwater level of ZK2 and ZK4,and the water of the seepage point does not go through the deep groundwater circulation.The leakage path is short,which may penetrate through the dissolution fracture and small karst hole at the inlet on the right bank of the dam site to the PD5 flat cave section between the dam and anti-seepage line on the right bank.The connectivity test shows that the karst cave(dissolution fracture)on the right bank upstream of the dam have good connectivity with the leakage outlet.Geophysical exploration results show that CT-2,CT-3 and CT-5,the main channels of fracture-type leakage distributed above the elevation of 630 m on the right bank,mainly control the leakage of dam foundation and around dam.Study results are shown as follows.(1)The leak

关 键 词：岩溶水库 渗透破坏 渗漏勘察 地下水温度场 物探CT 

分 类 号：TV697.3[水利工程—水利水电工程]