HDPE土工格室整体力学性能大型双轴拉伸试验  

Large scale biaxial tensile test on overall mechanical properties of HDPE geocell

作　　者：麻佳 宋玲[1] 刘杰 王斌 陈石 MA Jia;SONG Ling;LIU Jie;WANG Bin;CHEN Shi(College of Water and Architectural Engineering,Shihezi University,Shihezi 832003,Xinjiang,China;Xinjiang Transportation Planning Surveying and Design Institute,Urumqi 830000,Xinjiang,China;Lanzhou Deke Engineering Materials Co.,Ltd,Lanzhou 730000,Gansu,China)

机构地区：[1]石河子大学水利建筑工程学院,新疆石河子832003 [2]新疆维吾尔自治区交通规划勘察设计研究院,新疆乌鲁木齐830000 [3]兰州德科工程材料有限公司,甘肃兰州730000

出　　处：《长安大学学报（自然科学版）》2021年第6期29-38,共10页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51669031);新疆交通规划勘察设计研究院科研基金项目(KY2019092504)。

摘　　要：为了研究土工格室材料力学特性和变形规律,选择多组不同尺寸的高密度聚乙烯(HDPE)土工格室进行拉伸试验测试。首先,使用万能试验机分别对不同高度的条带进行拉伸试验,研究高度对条带强度的影响;然后,用节点拉伸试验机分别对不同高度土工格室节点进行拉伸,研究条带强度与节点强度之间的关系;最后,通过自主研发的双轴拉伸试验装置,以粒子图像测速(PIV)系统和电镜试验为测试途径,开展了土工格室大型双轴拉伸试验,提出了整体强度与条带强度力学特性模型。结果表明:HDPE土工格室整体变形包括节点变形和条带变形,土工格室条带伸长率与整体伸长率具有协同性,但条带伸长率小于整体伸长率,且前者一定时,高度大的土工格室整体伸长率较大;土工格室的整体强度与节点强度及条带强度有关,高度越大、每延米节点个数越多,土工格室具有更高的整体强度;双轴拉伸试验中节点先于条带破坏,因此,土工格室破坏强度由节点强度决定,拉伸破坏以后条带呈多纤维与拉伸方向同向分布,节点呈多层面撕裂状态,电镜试验也印证了这一观点。在工程设计中,土工格室设计强度的选择应注重节点强度与条带强度的匹配关系。To study the mechanical properties and deformation law of geocell materials,several groups of high density polyethylene(HDPE)geocells with different sizes were selected for tensile test.Firstly,the tensile tests of strips with different heights were carried out by universal testing machine to study the effect of height on strip strength.Then,the joints of geocell with different heights were stretched by joint tensile testing machine,and the relationship between strip strength and joint strength was studied.Finally,through the self-developed biaxial tensile test device,the PIV system and electron microscope test were used to carry out the large-scale biaxial tensile test of geocell,and the mechanical characteristics models of overall strength and strip strength were proposed.The results show that the overall deformation of HDPE geocell includes node deformation and strip deformation,the strip elongation and overall elongation of geocell have synergy,but the strip elongation is less than the overall elongation,and when the former is fixed,the overall elongation of geocell with higher height is larger.The overall strength of geocell is related to the joint strength and strip strength.The higher the height is,and the more number of joints per linear meter is,the higher the overall strength of geocell is.In the biaxial tensile test,the failure of the joint precedes that of the strip.Therefore,the failure strength of the geocell is determined by the strength of the joint.After the tensile failure,the strip is distributed in the same direction as the tensile direction,and the joint is in a multi-layer tearing state.The electron microscope test also confirms this view.In engineering design,the selection of geocell design strength should pay attention to the matching relationship between node strength and strip strength.2 tabs,12 figs,26 refs.

关 键 词：道路工程 路基工程 土工格室 双向拉伸试验 条带 节点 力学性能 

分 类 号：U411[交通运输工程—道路与铁道工程]