摘要
采用三维激光扫描技术,提出基于真实颗粒外形的可破碎道砟单元构造方法,在此基础上通过离散元法建立洛杉矶磨耗试验的精细化数值仿真模型;结合室内试验结果对数值模型进行标定与验证,重点研究《TB/T 2140—2008铁路碎石道砟》中规定的针、片状道砟颗粒对道砟集料在循环荷载作用下劣化演化机制及动力特性的影响规律。结果表明:针状道砟颗粒会严重削弱道砟集料的整体耐磨性能,且极易发生转动;片状颗粒对道砟集料的整体耐磨性能影响不明显,且在循环荷载作用下具有较好的动态稳定性。仅就道砟的磨耗性能而言,建议相关规范在规定针、片状颗粒含量时综合考虑整体耐磨性能和动态稳定性。
Using three-dimensional laser scanning technology,a construction method of crushable railway ballast discrete element based on real ballast shape was proposed.A refined numerical simulation model of Los Angeles Abrasion test was built with discrete element method.The results of laboratory experiment were used to verify the numerical model.The influence of needle and flaky shape ballast stipulated by industrial standard on wear mechanism and dynamic characteristics of ballast aggregate during cyclic loading was focused during the research.The results show that needle shape ballast not only weakens the wear-resisting property of ballast aggregate observably but also easy to rotate.However,the flaky shape ballast does not have obvious influence on wear-resisting property of ballast aggregate,while it shows good dynamic stability during cyclic loading.As far as the wear-resisting property of ballast is concerned,the wear-resisting property and dynamic stability should be taken into account when the needle and flaky shape ballast rate limit is stipulated in relevant codes.
作者
徐旸
高亮
杨国涛
侯博文
殷浩
XU Yang;GAO Liang;YANG Guotao;HOU Bowen;YIN Hao(Railway Engineering Research Institution,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2019年第2期124-129,共6页
Journal of the China Railway Society
基金
国家自然科学基金(51808556
51808557)
中国铁路总公司科技研究开发计划(N2018G041)
关键词
铁路碎石道砟
三维激光扫描
离散元法
磨耗性能
railway ballast
three-dimensional laser scanner
discrete element method
wear-resisting property
