摘要
为揭示高速铁路路基粗粒土填料颗粒破碎过程,构建室内单元模型,模拟粗粒土填料填筑和列车荷载作用过程,重点探讨动应力幅值、加载频率及降雨入渗强度等因素对颗粒破碎的影响。利用2个颗粒破碎度量指标分析粗粒土填料的颗粒破碎过程。研究结果表明:粗粒土填料在填筑时,颗粒破碎方式以破裂、破碎为主,在动力循环荷载作用下,颗粒破碎方式以破裂、研磨为主;破碎指标B_(g),ΔD随动应力幅值、加载频率的增大而增加,随降雨入渗强度的增加呈先增大后减小的趋势;粗粒土填料破碎后,粒径分布具有良好的分形特性,且分形维数D与颗粒破碎指标B_(g)存在良好的线性关系。利用试验结果建立了动力循环荷载作用下粗粒土填料破碎指标ΔD与累积应变ε的关系表达式。
Particle breakage of coarse-grained soil filling significantly affects its engineering properties.In order to investigate the process of particle breakage of coarse-grained soil filling of high-speed railway subgrade,the test model was conducted.The filling and train load process of coarse-grained soil filling was simulated by stratified compaction test and dynamic cyclic loading test.The paper studied on the effects of dynamic stress amplitude,loading frequency and rainfall infiltration intensity on particle breakage,and analyzed the process of particle breakage by particle breakage index B_(g) and fractal dimension.The results show that the main mode of particle breakage is fracture and attrition during the filling process,while after the dynamic load,the main mode of is fracture and abrasion.The particle breakage index B_(g) and the difference of fractal dimensionΔD increase with the increase of dynamic stress amplitude and loading frequency,and with the increase of rainfall infiltration intensity,the trend is to increase first and then decrease.The particle size distribution has a good fractal feature after the whole process of coarse-grained soil filling is broken.A good linear regression relation exists between fractal dimension D and particle breakage index B_(g).In this paper,the formula expression between particle breakage indexΔD and cumulative strainεof coarse-grained soil filling under dynamic cycle loading was established.
作者
王启云
肖南雄
张丙强
项玉龙
魏心星
WANG Qiyun;XIAO Nanxiong;ZHANG Bingqiang;XIANG Yulong;WEI Xinxing(College of Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;Key Laboratory of Underground Engineering,Fujian Province University,Fujian University of Technology,Fuzhou 350118,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2021年第5期1071-1080,共10页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51508097)
福建省杰出科研青年人才培育计划项目(GY-Z160147)
福建省自然科学基金资助项目(2020J01884)。
关键词
路基
粗粒土
颗粒破碎
分形维数
subgrade
coarse-grain soil
particle breakage
fractal dimension
作者简介
通信作者:王启云(1986−),男,湖南祁阳人,副教授,博士,从事路基动力学方面的研究,E−mail:wangqiyun860519@163.com。
