混凝土防渗墙施工缺陷对其渗透溶蚀演化规律的影响  

Influences of construction defects of concrete cutoff walls on evolution laws of their leakage dissolution

作　　者：甘磊[1,3] 刘源 张宗亮 沈振中 郑光和[3] GAN Lei;LIU Yuan;ZHANG Zongliang;SHEN Zhenzhong;ZHENG Guanghe(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;Power Construction Corporation of China,Ltd.,Beijing 100048,China;Research Center for Embankment Safety and Disaster Prevention Engineering Technology of the Ministry of Water Resources,Zhengzhou 450003,China)

机构地区：[1]河海大学水利水电学院,江苏南京210024 [2]中国电力建设集团有限公司,北京100048 [3]水利部堤防安全与病害防治工程技术研究中心,河南郑州450003

出　　处：《岩土工程学报》2023年第6期1269-1277,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52179130);江苏省自然科学基金项目(BK20201312);水利部堤防安全与病害防治工程技术研究中心项目(DFZX2020003)。

摘　　要：渗流作用下防渗墙施工缺陷对其渗透溶蚀演化进程影响较显著,为探究防渗墙相邻槽段搭接不良和墙底分叉对其渗透溶蚀的影响机制,结合流体和化学动力学相关理论,建立含施工缺陷的混凝土防渗墙渗透溶蚀耦合分析模型。结合某土工膜防渗砂砾石坝,研究两种缺陷形式下防渗墙中钙离子浓度、孔隙率及渗流特性变化规律。防渗墙钙离子浓度随服役年份增长不断降低,且缺陷越严重,浓度越低;孔隙率随服役年份呈指数型增长,服役100 a后孔隙率增大约1.83倍;防渗性能随服役年份、接缝宽度和分叉高度的增长而减弱,相比防渗墙完好工况,当接缝宽度3.0 cm或分叉高度为3 m时,服役100 a后防渗墙等效渗透系数分别增大了8.20倍,40.38倍,大坝总渗流量分别增大了4.49倍,5.81倍。研究成果可为土石坝工程长效服役性能评估提供理论支撑。Under the action of seepage,the construction defects of cutoff walls have a significant impact on the evolution process of their leakage dissolution.In order to investigate the influence mechanism of poor overlapping of the adjacent groove sections and the bottom bifurcation of the cutoff walls,based on the relevant theories of fluid dynamics and chemical dynamics,a coupling analysis model for leakage dissolution of concrete cutoff walls with construction defects is proposed.Based on a sand gravel dam project with geomembrane anti-seepage measure,the variation laws of calcium ion concentration,porosity and seepage characteristics of the concrete cutoff walls under two types of defects are revealed.The calcium ion concentration of the cutoff walls decreases with the increase of service year,and the more serious the defects are,the lower the concentration of calcium ion is.The porosity increases exponentially with the service year,and the maximum porosity increases by about 1.83 times after 100 service years.The anti-seepage performance of the cutoff walls decreases with the increase of the service year,joint width and bifurcation height of the construction defects.Compared with the intact condition of the cutoff walls,when the joint width is 3.0 cm or the bifurcation height is 3 m,the equivalent permeability coefficient of the cutoff walls increases by 8.20 times and 40.38 times respectively after 100 service years,and the total seepage flow of the dam body and dam foundation increases by 4.49 times and 5.81 times,respectively.The research results can provide theoretical support for evaluating the long-term service performance of earth-rock dams.

关 键 词：混凝土防渗墙 施工缺陷 渗透溶蚀 孔隙率 渗流特性 

分 类 号：TU528.36[建筑科学—建筑技术科学]