岩土工程学报2016，Vol.38Issue(6)：1147-1151,5.DOI:10.11779/CJGE201606023
土工膜环向约束气胀变形试验研究
Experimental study on air expansion deformation of geomembrane under ring-restrained conditions
摘要
Abstract
For the surrounding dam plain reservoirs that use a horizontal anti-seepage scheme, the leakage of reservoir water, rise in groundwater table and other reasons lead to the pore gas in unsaturated soil under the geomembrane gather, rise and change into pressure, which can cause geomembrane air expansion with local swelling. According to its characteristics, the air expansion deformation of geomembrane is simplified as the spherical bulging deformation under ring-restrained conditions. A set of test equipment with four different diameters is developed to study the characteristics of air expansion deformation of geomembrane under ring-restrained conditions, and the influence of the diameter of test equipment on burst pressure of geomembrane is analyzed. The test equipment with outside diameter of 20 cm is selected as the basic equipment of air expansion of geomembrane. A test is conducted using the selected equipment, and the rules of air expansion deformation and failure of geomembrane are summarized. The conclusions are drawn as follows: (1) The stress-strain curves of air expansion deformation of geomembrane can be divided into four stages: linear deformation, strengthening deformation, weakening deformation and bursting break. (2) The air expansion deformation is not uniform, the mechanism of air expansion failure is the tension failure, and the failure mode is a great circle curve through the vertex of spherical cap or a small round curve which does not pass through the vertex of the spherical cap. (3) For the geomembrane with thickness of 0.35 ~ 0.6 mm, the burst pressure of air expansion is 0.08 ~ 0.12 MPa, and the air expansion crown height is 4.6 ~ 5.5 cm. (4) For the geomembrane wiht thickness of 0.35 ~ 0.6 mm, the air expansion elongation is 17.6% ~ 18.5%, which is far less than the unidirectional tensile elongation of geomembrane.关键词
平原水库/库盘防渗/土工膜/气胀变形/胀破压力/气胀延伸率/胀破冠顶高度Key words
plain reservoir/anti-seepage of reservoir basin/geomembrane/air expansion deformation/burst pressure/air expansion elongation/air expansion crown height分类
建筑与水利引用本文复制引用
李旺林,刘占磊,孟祥涛,徐芳..土工膜环向约束气胀变形试验研究[J].岩土工程学报,2016,38(6):1147-1151,5.基金项目
山东省自然科学基金项目（ZR2014EFM023）；山东省科技计划项目 （）
