白鹤滩水电站阶段性蓄水过程坝基渗流状态分析  

An Analysis of the Seepage State of Dam Foundation during the Stage Impoundment of Baihetan Hydropower Station

作　　者：张胡琦 荣冠[1] 陈文夫 谭尧升 邱钦焱 徐李达 ZHANG Hu-qi;RONG Guan;CHEN Wen-fu;TAN Yao-sheng;QIU Qin-yan;XU Li-da(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,Hubei Province,China;China Three Gorges Construction(Group)Company Limited,Chengdu 6100411,Sichuan Province,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]中国三峡建工(集团)有限公司,四川成都610041

出　　处：《中国农村水利水电》2023年第5期223-231,共9页China Rural Water and Hydropower

基　　金：白鹤滩大坝全过程三维渗流场模型构建与库水-坝基-结构动态耦合仿真研究(BHT/0811)。

摘　　要：白鹤滩水电站自2021年4月6日开始蓄水,至2021年9月30日水位最高达816.51 m,此后水位开始回落,2022年2月底水位降至790 m左右。根据阶段性蓄水过程中的渗流监测成果,结合坝址区工程地质条件及渗控布置方案,分析了白鹤滩水电站大坝坝基的渗流状态,并推测了坝基可能存在的渗漏通道。分析结果表明,河床坝基渗流量受上游水位影响较大,蓄水以来,河床坝基渗流量最大达1226.37 L/min,较蓄水前增加784.78 L/min,且增加量主要集中在15号、16号坝段,而左右岸坝基渗流量相对较小,两岸坝基渗流量同时受上游水位及降雨量的影响;816.51 m蓄水位下帷幕前扬压力折减系数为0.73~0.97,帷幕后为0.07~0.30,主排水幕处为0~0.07,在防渗排水系统的作用下,坝基扬压力得到了有效消减;推测认为渗透水流通过防渗帷幕薄弱部位流向下游,并以P2β32-2和P2β32-1为主要导水地层,结合地层内发育的软弱结构面向坝基排水孔汇渗,造成部分坝段渗流量显著大于其他坝段。总的来说,阶段性蓄水过程中大坝坝基渗流状态稳定,大坝渗控布置方案合理,渗控效果良好。Baihetan Hydropower Station started water storage on April 6,2021,and the water level reached a maximum of 816.51m on Sep⁃tember 30,2021,after which the water level began to fall back to about 790 m at the end of February 2022.Based on the seepage monitoring data during stage impoundment,the engineering and geological conditions of the dam site area and the seepage control arrangement scheme,the seepage state of the dam foundation of Baihetan Hydropower Station is analyzed and the possible seepage channels of the dam foundation are speculated.The analysis results show that the seepage volume of the riverbed foundation is influenced by the upstream water level.The water storage,the maximum seepage volume of the riverbed foundation reaches 1226.37 L/min,which is 784.78 L/min higher than that be⁃fore the water storage.Besides,the increase mainly concentrated in 15#and 16#dam sections.Nevertheless,the seepage volumes of the left and right bank foundations are relatively small,and are affected by the upstream water level and rainfall.At 816.51 m water level,the reduc⁃tion coefficients of the lifting pressure before the curtain are 0.73~0.97,after curtain are 0.07~0.30,and at the main drainage curtain are 0~0.07.The uplift pressure at the foundation of the dam is effectively reduced because of the presence of the seepage control system.It is pre⁃sumed that the leakage water flows downstream through the weak part of the impermeable curtain,with strata P2β32-2 and P2β32-1 as the main water-conducting stratum.Combined with the weak structure developed in the stratum,the leakage water flows toward the drainage holes lo⁃cated in the dam foundation,resulting in a significantly higher seepage volume in some dam sections than in others.In general,the seepage state of the dam foundation is stable during the stage impoundment.Besides,the seepage control arrangement scheme of the dam is reason⁃able and the seepage control effect is good.

关 键 词：白鹤滩大坝 监测资料 渗流 渗漏通道 

分 类 号：TV698.12[水利工程—水利水电工程]