分级加载下铁路路基粗粒土动力特性研究  

Study on dynamic characteristics of coarse grained soil filler in railway subgrade under stepped axial cyclic loading

作　　者：李扬波[1] 张家生[1,2] 朱志辉[1,2] 王晅[1,2] 石熊[1] LI Yangbo;ZHANG Jiasheng;ZHU Zhihui;WANG Xuan;SHI Xiong(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Laboratory for High Speed Railway Construction,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《铁道科学与工程学报》2019年第3期620-628,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51678576;51378514)

摘　　要：利用大型动三轴试验仪对铁路路基粗粒土填料开展分级加载的循环三轴试验,分析围压、加载频率对粗粒土动应力-动应变关系、动弹模以及阻尼比等动力特性的影响。试验结果表明:随着围压或频率的增加,土体的动强度、动弹性模量和阻尼比均增大;动应变较小时频率或围压对阻尼比的影响较小,动应变较大时频率或围压对阻尼比影响较大。在试验基础上建立基于Hardin-Drnevich骨架曲线和符合广义Masing准则的粗粒土非线性动本构模型,并在ABAQUS中UMAT二次开发平台编制相应的子程序。通过与试验结果比较,验证了粗粒土非线性动本构模型的正确性。A large scale dynamic triaxial test apparatus was used to carry out cyclic triaxial tests on Railway Subgrade coarse grained soil fillers.The effects of confining pressure and loading frequency on the dynamic stress-strain relationship,dynamic modulus and damping ratio of coarse grained soil were analyzed.The experimental results show that with the increase of confining pressure or frequency,the dynamic strength,dynamic elastic modulus and damping ratio of the soil increase.When the dynamic strain is small,the influence of frequency or confining pressure on damping ratio is relatively small,and the larger the dynamic strain is,the greater the impact is.On the basis of experiments,a dynamic nonlinear constitutive model of coarse grained soil based on Hardin-Drnevich skeleton curve and generalized Masing criterion is established,and the corresponding subroutine(UMAT)is compiled on the secondary development platform of ABAQUS.The correctness of the dynamic nonlinear constitutive model of coarse-grained soil is verified by comparison with the experimental results.

关 键 词：粗粒土 大型动三轴试验 动弹性模量 阻尼比 二次开发 

分 类 号：TU44[建筑科学—岩土工程]