复合土工膜在引黄闸防渗中的应用
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摘要
涵闸底板与铺盖连接处易产生不均匀沉降,导致黏土防渗体破坏,危害涵闸及大堤安全。复合土工膜与黏土铺盖组合结构抵抗变形能力强,可作为闸室底板与闸前铺盖间防渗体。以山东杨集引黄闸为例,建立涵洞式水闸三维模型,在平衡地应力后,对闸室底板施加实测位移荷载,研究实际沉降条件下复合土工膜的应力变形规律。计算结果表明:复合土工膜最大应力均出现在底板底部拐角处,纵向最大拉应力为4.30 MPa,横向最大拉应力为3.54 MPa,小于土工膜的允许抗拉强度,可满足工程应用要求,其变形规律依附于闸基的沉降,纵向位移与闸基沉降基本相等。针对直角拐角处应力集中现象,可在横、纵向折叠铺设土工膜,以减小拉应力。
The differential settlements at the joint between base board and up-stream blanket are the main causes of the clay anti-seepage structure damage,endangered the safety of sluices and banks. Because of the good deformation resistance capacity,composite geo-membrane( CG) and clay blanket composite structure can be used as the anti-seepage body between the base board and the blanket. In order to study the stress and deformation characteristics of CG,taking Shandong Yangji sluice as an example,it established 3D model and applied the actual measured displacement load to the base board after balancing the geo-stress. The result indicates that the maximum longitudinal tensile stress is 4.3 MPa and the maximum horizontal tensile stress is 3.5 MPa,far below the tensile limits of CG. This composite structure can satisfy the application requirements. The deformation of CG is consistent with the sluice foundation. The vertical deformation is 70.52 mm. For the stress concentration zones at the vertical corner,CG can be folded along the vertical and horizontal directions before laying on the ground.
The differential settlements at the joint between base board and up-stream blanket are the main causes of the clay anti-seepage structure damage,endangered the safety of sluices and banks. Because of the good deformation resistance capacity,composite geo-membrane( CG) and clay blanket composite structure can be used as the anti-seepage body between the base board and the blanket. In order to study the stress and deformation characteristics of CG,taking Shandong Yangji sluice as an example,it established 3D model and applied the actual measured displacement load to the base board after balancing the geo-stress. The result indicates that the maximum longitudinal tensile stress is 4.3 MPa and the maximum horizontal tensile stress is 3.5 MPa,far below the tensile limits of CG. This composite structure can satisfy the application requirements. The deformation of CG is consistent with the sluice foundation. The vertical deformation is 70.52 mm. For the stress concentration zones at the vertical corner,CG can be folded along the vertical and horizontal directions before laying on the ground.
引文
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[3]付振国,沈长松.高面膜堆石坝受力变形特性及结构设计研究[J].人民黄河,2017,39(6):110-114.
[4]束一鸣,吴海民,姜晓桢.中国水库大坝土工膜防渗技术进展[J].岩土工程学报,2016,38(增刊1):1-9.
[5]李兴平.土工合成材料在引黄涵闸中的应用[J].人民黄河,1989,11(1):32-34.
[6]吴跃东,殷宗泽,郭纪中.真空联合堆载预压法加固水工建筑物软基效果检验[J].岩土力学,2007,28(4):738-742.
[7]杨汉锡.关于胜丰涵闸基础地质变化采取措施的简要分析[J].科技资讯,2015(11):62.