土工织物顶压蠕变特性与折减系数研究  

Study on creep property and reduction coefficient of geotextiles under top pressure

作　　者：李丹[1,2] 易杨 罗琛 吴迪 徐超 吴建建[2] LI Dan;YI Yang;LUO Chen;WU Di;XU Chao;WU Jianjian(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;School of Architecture and Transportation Engineering,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]桂林电子科技大学建筑与交通工程学院,广西桂林541004

出　　处：《水利学报》2023年第10期1210-1220,1235,共12页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(42067044);广西重点研发计划项目(桂科AB23026028)。

摘　　要：常规土工合成材料蠕变特性仅考虑筋材拉伸状态。随着土工合成材料应用愈加广泛,其受力条件也愈加复杂。为研究土工织物在受到顶压力作用下的蠕变特性,研制了顶压蠕变试验装置。采用该装置对Mirafi PET 1300土工织物进行了CBR圆形顶破试验以及40%、50%和60%三种荷载水平下的2400 h圆形顶压蠕变试验,计算了5、10、60和120 a设计年限在不同顶压面积应变下的顶压蠕变折减系数,并与常规拉伸蠕变折减系数对比,建立了顶压蠕变折减系数、设计年限与顶压面积应变三者的量化关系式,以预测顶压蠕变折减系数。结果表明,对于试验土工织物,顶压蠕变折减系数比常规拉伸蠕变折减系数大65.340%~148.496%;随设计年限的增加,顶压蠕变折减系数变化不大;在不同设计年限下,随顶压面积应变的增加,顶压蠕变折减系数保持平稳。为提升工程结构的安全性和耐久性,在土工合成材料受顶压作用情况下,建议设计采用顶压蠕变折减系数。The creep properties of routine geotextiles only consider the tensile state of the reinforcement.The stress conditions of geotextiles are more complex with the wide application.In order to study the creep property of geotextiles under top pressure,a top pressure creep test apparatus was developed.The CBR circular puncture test of Mirafi PET 1300 geotextile and 2400 hours circular top pressure creep tests under the load levels of 40%,50%and 60%were carried out using this apparatus.The top pressure creep reduction coefficients under different failure strains and different design lives of 5 years,10 years,60 years and 120 years were calculated,which were compared with the regular tensile creep reduction coefficients.The quantitative relation among the creep reduction coefficient,design life and failure strain were established to predict the top pressure creep reduction coefficient.The results showed that the top pressure creep reduction coefficient was greater than that of regular tensile creep and the improvement range was from 65.340%to 148.496%.The creep reduction coefficient had little change with the increase of design life.The top pressure creep reduction coefficient kept stable with the increase of top pressure area strain under different design lives.To improve the safety and durability of engineering structures,it is suggested that the top pressure creep reduction coefficient should be used in the design of the geosynthetics affected by top pressure.

关 键 词：土工合成材料 顶压蠕变特性 蠕变折减系数 顶压蠕变试验装置 量化关系式 

分 类 号：TU531.7[建筑科学—建筑技术科学]