高堆石坝面防渗土工膜锚固区夹具效应破坏模型试验  

Model tests on failure properties of geomembrane anchorage due to clamping effect in surface barrier of high rock-fill dam

作　　者：吴海民[1] 束一鸣[1] 滕兆明[1] 蒋善平[1] 刘云锋[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《岩土工程学报》2016年第S1期30-36,共7页Chinese Journal of Geotechnical Engineering

基　　金：长江科学院开放研究基金项目(CKWV2015210/KY);国家自然科学基金项目(51409083;51379069);江苏高校优势学科建设工程项目(PAPD)

摘　　要：针对高堆石坝面防渗土工膜锚固区易因夹具效应而发生拉伸破坏的问题,运用自研锚固结构模型试验装置对堆石坝面膜防渗体周边锚固结构处土工膜"夹具效应"破坏特性进行了一系列模型试验验证和分析。试验结果表明,在坝基和防渗墙或者坝面与岸坡岩体间发生差异沉降后,锚固区极小范围内的土工膜随接触材料一起发生位移而无法发生相对运动是夹具效应破坏的根源;传统直线型、折叠式及缠绕式铺膜锚固方式均无法避免因夹具效应而发生拉伸破坏;相同差异位移条件下,PVC膜承受差异变形的能力相对于PE和HDPE膜更强,在深覆盖层上高堆石坝防渗中应该首先考虑使用。Tension failure of geomembrane in anchorage zone of surface barrier for high rock-fill dams will be inevitably caused by clamping effect. A set of model tests are performed to verify and analyze the failure properties of geomembrane due to the clamping effect in the anchorage zone of surface barrier using self-developed devices. The test results show that the geomembrane cannot move freely and yield tension failure when differential settlement occurs between dam foundation and cutoff wall or dam surface and rock of bank slope. The excessive friction between the geomembrane and the contacting material is the main reason of tension failure of the geomembrane in small anchorage zone. The traditional anchoring structures including line-shaped anchorage, spirally wrapped anchorage and folded anchorage will all inevitably induce the excessive tension defamation of geomembrane next to their connection to anchorage structure. Under the same differential settlement, PVC geomembrane exhibits a stronger adaptability to the differential deformation compared with to PE and HDPE geomembranes. So the PVC geomembrane should be a preferred selection when used as the surface barrier for high rock-fill dam on thick pervious foundation.

关 键 词：堆石坝 土工膜防渗体 锚固结构 夹具效应 模型试验 

分 类 号：TV223.4[水利工程—水工结构工程] TV49