摘要
针对在一定水深下,面膜周边锚固处将形成"面膜夹具"进而产生影响面膜安全的夹具效应这一高面膜堆石坝研究和设计中首先需面对的关键技术问题,在材料试验和工程结构分析的基础上分析了形成夹具效应的机制,提出了产生夹具效应的必要条件和充分条件;模拟工程实际设计了面膜堆石坝周边锚固处夹具效应的室内结构模型试验,初步试验验证了按常规设计的传统膜铺设方式难以避免夹具效应的产生;在充分考虑实际施工工艺的基础上,以夹具效应产生的充分条件为切入点提出了消除夹具效应的设计思路为:在保证面膜免受损伤条件下增大"面膜夹具"间的初始标距,在坝体位移过程中设法使"面膜夹具"间面膜的有效几何变形取代材料变形;设计方法是将铺膜线平面设置高于锚固线平面,坝面位移后使铺膜线回到锚固线附近。
A key technology issue firstly faced in studding and designing membrane faced rockfill dam ( MFRD) is that at perimeter of surface membrane, under definite depth of water, “anchorages of surface membrane“ are formed and then“anchoring influences“, affecting the safety of faced membrane, are produced. Based on material test and structure analysis, the forming mechanism of anchoring influence is analyzed and the necessary and sufficient conditions of anchoring influence formed are proposed. After designing structure experiment model of anchoring influence at perimeter of surface membrane on MFRD, it is proved by preliminary experiment that anchoring influence cannot be avoid if surface membrane is placed on dam according to traditional way. Based on a full consideration of construction technology and sufficient conditions of anchoring influence formed, the idea of eliminating anchoring influence under the condition of no damage of surface, one should increasing the initial gauge length between anchorages of surface membrane in order to substitute geometry deformation for the material deformation between anchorages of surface membrane during dam displacement. The approach of design is that the paving line of surface membrane is high to anchoring line, thus the paving line of surface membrane goes back to anchoring line after displacement of the dam surface.
出处
《水利水电科技进展》
CSCD
北大核心
2015年第1期10-15,共6页
Advances in Science and Technology of Water Resources
基金
国家自然科学基金(51079047
51379069)
关键词
面膜堆石坝
土工膜
夹具效应
周边锚固
膜拉伸试验
结构模型试验
设计方法
membrane faced rockfill dam(MFRD)
geomembrane
anchoring influence
perimeter anchoring
membrane tension test
structure model experiment
design approach
