超深覆盖层上沥青混凝土心墙坝防渗体应力变形特性及处理措施研究

Research on Stress and Deformation Characteristics and Measures of Anti-seepage Structure of Asphalt Concrete Core Dam on Ultra-deep Overburden

防渗体系是保证深厚覆盖层地基上沥青混凝土心墙坝安全运行的最重要结构,其安全性备受关注。因此,对超深覆盖层上沥青混凝土心墙坝开展了大规模的三维有限元分析,研究了防渗体系在填筑和蓄水过程中的应力变形特性。结果表明,沥青混凝土心墙两岸局部区域的拉应变相对较大,应重点关注;嵌入两岸的廊道设计导致廊道及防渗墙顶部两端出现高应力区;在廊道和两岸之间设置结构缝或波纹管,可有效改善廊道和防渗墙应力状态。研究成果为超深覆盖层上土石坝防渗体的设计、优化和安全评价提供了支撑。

The anti-seepage system is the most important structure to ensure the safe operation of asphalt concrete core dam on ultra-deep overburden foundations,and its safety has received much attention.This article conducts a largescale three-dimensional finite element analysis of asphalt concrete core dams on ultra-deep overburden,and studies the stress deformation characteristics of the anti-seepage system during the filling and impoundment processes.The results indicate that the tensile strain in the local areas on both sides of the asphalt concrete core is relatively large,and should be given special attention.The design of the gallery embedded on both sides leads to high stress zones at both ends of the gallery and the top of the cutoff wall.Setting structural joints or corrugated pipes between the gallery and both banks can effectively improve the stress state of the gallery and cutoff wall.The research can provide support for anti-seepage body design,optimization and safety evaluation of earth and rockfill dam on ultra-deep overburden.