摘要
为了探讨粗粒土路基在往复列车荷载作用下产生的累积变形和动力特性,开展了粗粒土的室内动三轴试验,分析了不同循环应力比、不同围压对粗粒土路基累积变形的影响。根据动三轴试验结果,提出了考虑围压和循环应力比影响的粗粒土路基累积变形模型。研究结果表明:循环应力比为0.3时是加载次数-累积动应变曲线由稳定型向破坏型演化的起点,随着循环应力比的增大,软化指数不断增大;当循环应力比小于0.3时,软化指数随着围压的增大而减小,当循环应力比大于0.3时,软化指数随着围压的增大而增大。累积变形模型反映循环应力比和围压对累积动应变的影响,能较好地预测累积动应变的发展趋势,且模型参数有明确的物理意义,能为粗粒土路基的设计和养护提供参考。
In order to study accumulated deformation and dynamic properties of coarse-grained soil foundation under cyclical train loading,a dynamic triaxial test was conducted.The effects of cycling stress ratio(CSR) and confining pressure on accumulated deformation behavior were analyzed.Based on the results of the dynamic triaxial tests,an accumulated deformation model considering the impacts of confining stress and CSR was developed.The results show that the loading times-accumulated dynamic strain curve starts to transfer stable type to damage type when CSR is 0.3.With increasing of CSR,softening index is increasing.When CSR is smaller than 0.3,the softening index is decreasing with the confining press;but when CSR is larger than 0.3,the softening index is increasing with the confining press.The accumulated deformation model can reflect the effects of CSR and the confining press on accumulated deformation,and it can predict the accumulated deformation development tendency.The model parameters have explicit physical meaning.It is expected to provide reference to the design and maintenance of coarse grained foundation.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第16期128-133,158,共7页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(51378514)
关键词
铁路路基
循环荷载
累积变形模型
动三轴试验
粗颗粒土
railway foundation
cyclic load
accumulated deformation model
dynamic triaxial test
coarse-grained soil
