摘要
复合土工膜的动应力应变关系预测是土石坝防渗工程长期运营涉及的关键问题之一。为研究循环荷载作用对复合土工膜应力应变的影响,开展了10%、20%、30%共3个不同应力水平下循环加载-卸载试验,并进行10%~80%应力水平下复合土工膜的蠕变试验,对比分析其蠕变和蠕变恢复特性,提出了循环加载累积条件下应变的表达式,构建了循环加载条件下复合土工膜边界面的本构模型。研究结果表明:复合土工膜在加载和卸载的瞬间,变形量会瞬时增加,之后会随着时间的增长而逐渐变缓;完全卸载后,当应力水平低于30%时,复合土工膜变形几乎能恢复;当应力水平大于等于40%时,随着应力水平的增加,残余变形逐渐增大。循环加载次数对土工膜蠕变变形的影响并不是呈简单的线性关系;此外,建立了改进的三参数黏弹模型,并验证了该模型能够较好地复现复合土工膜在不同荷载水平下的蠕变恢复过程。研究成果可为复合土工膜在土石坝中的长期变形分析提供参考依据。
The prediction of dynamic stress-strain relationship of composite geomembrane is one of the key problems involved in the long-term operation of seepage prevention projects of earth-rock dams.In order to study the effect of cyclic loading on the stress and strain of the composite geomembrane,cyclic loading and unloading tests were carried out under three different stress levels of 10%,20%and 30%,and the creep tests under 10%to 80%stress levels were carried out to compare and analyze the creep and creep recovery characteristics of the composite geomembrane.The expression of strain under cyclic loading and accumulation condition was presented,and the constitutive model of composite geomembrane boundary surface under cyclic loading condition was constructed.The results show that the deformation of composite geomembrane increases instantaneously at the moment of loading and unloading,and then gradually slows down with the increase of time.After complete unloading,when the stress level is less than 30%,the deformation of the composite geomembrane can almost recover.When the stress level is greater than or equal to 40%,the residual deformation increases gradually with the increase of the stress level.The effect of cyclic loading times on the creep deformation of geomembrane is not a simple linear relationship.In addition,an improved three-parameter viscoelastic model was established,and it is verified that the model can reproduce the creep recovery process of composite geomembrane under different load levels.The research results can provide a reference for the long-term deformation analysis of composite geomembrane in earth-rock dams.
作者
马书涵
李晓林
杨武
刘亮
杨海华
MA Shu-han;LI Xiao-lin;YANG Wu;LIU Liang;YANG Hai-hua(College of Water Conservancy and Civil Engineering,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Hydraulic Engineering Geotechnical and Structural Engineering Technology Research Center,Urumqi 830052,China)
出处
《科学技术与工程》
北大核心
2025年第17期7337-7343,共7页
Science Technology and Engineering
基金
新疆维吾尔自治区自然科学基金(2022D01B105)
新疆维吾尔自治区人才发展基金“天池英才”引进计划。
关键词
复合土工膜
循环荷载
蠕变
蠕变恢复
三参数黏弹模型
composite geomembrane
cyclic loading
creep
creep recovery
three parameter viscoelastic constitutive model
