关键词: 拱坝, 坝基, 渗流量, 安全监测, 伪随机流场法

Abstract: A high arch dam is located in an alpine valley with complex hydrogeological conditions. After impoundment, significant seepage has occurred in multiple drainage holes of the drainage tunnel of dam foundation on the left bank, which is a key concern of the project. To identify the cause of the seepage, based on the hydrogeological conditions during impoundment, seepage control and treatment measures, pseudo-random flow field method detection results, monitoring and inspection results, combined with nearly 10-year monitoring data under the 80 m cycle of reservoir water level fluctuation, a comprehensive analysis is conducted on the characteristics of seepage and seepage pressure in the drainage tunnel and behind the curtain, as well as the source of seepage. The results indicate that the curtain in dam foundation of the left bank is effective, the seepage and seepage pressure have decreased year by year and tend to stabilize, and the seepage volume is much smaller than the design pumping and drainage capacity of the dam foundation drainage well. The seepage mainly comes from mountain groundwater and downstream river water, and the seepage is safe and controllable.

Key words: arch dam, dam foundation, seepage volume, safety monitoring, pseudo random flow field , method