水力发电学报2025，Vol.44Issue(10)：29-38,10.DOI:10.11660/slfdxb.20251003
堆石坝心墙防渗土工膜力学特性试验及材料选型研究
Mechanical property tests and material selection of geomembrane for seepage control in core-wall rockfill dams
摘要
Abstract
Deformation behavior of seepage-control geomembranes in the core wall of a rockfill dam is crucial to the safety of its seepage-control system.However,conventional uniaxial tensile tests are of low accuracy in modeling the multidirectional stress state that dominates the operation of a geomembrane.To clarify the deformation capacity of a geomembrane under its real operating conditions,this study puts forward a solution to the challenges in material selection for a rockfill dam core wall,conducts comparative uniaxial and multiaxial tensile tests on three geomembrane materials-HDPE,LLDPE and PVC commonly used in dam seepage-control systems-and examines the mechanical properties of these geomembranes.The findings reveal traditional uniaxial tests overestimate the deformability of geomembranes-the yield strains of HDPE and LLDPE under multiaxial tension(1.6％-2.4％)are significantly lower than those under uniaxial tension(13％),while PVC exhibits no distinct yield point.However,PVC geomembrane demonstrates ultimate tensile strains(92.8％-112.4％)that far exceed those of PE(by 34.4％-50.0％).If elastic-stage strain energy density is used to evaluate deformation adaptability,PVC exhibits the highest elastic strain energy density under multiaxial loading,substantially greater than both PE variants,and thicker PVC geomembranes show greater deformation accommodation capacity.This study demonstrates the elastic strain energy density derived from multiaxial tensile tests can serve as a reliable criterion for assessing deformation performance of seepage-control geomembranes.关键词
心墙堆石坝/防渗土工膜/变形能力/弹性应变能/选型方法Key words
core-wall rockfill dam/geomembrane/deformation ability/elastic strain energy/selection method分类
建筑与水利引用本文复制引用
刘乾坤,吴海民,刘一铎,赵泓宇,汪万升,刘宝永..堆石坝心墙防渗土工膜力学特性试验及材料选型研究[J].水力发电学报,2025,44(10):29-38,10.基金项目
国家自然科学基金项目(51379069 （）
51409083) （）
