摘要
铁路碎石道床的道砟级配对道床的力学性能具有显著的影响,采用三维激光扫描技术对道砟颗粒的形状特征进行了获取及分析,并提出了基于道砟外形重建结果的离散元颗粒数值模型构造方法;在此基础上建立了循环荷载道砟箱数值模型。以此研究在高速及重载线路条件下,道砟级配对散体道床动力沉降特性的影响规律,并从细观角度分析了道床的沉降机理。研究结果表明:不同运营条件下铁路碎石道床的沉降机理有所不同。道砟颗粒间的相互错动是引发重载铁路道床沉降主要原因。而对于高速铁路,道床沉降还会受到高频荷载作用下颗粒自身转动的影响。因此,建议在规范中针对不同的线路条件提出不同的道砟级配曲线要求。
Ballast gradation has obviously an influence on ballast bad’s dynamic performances. The three-dimensional laser scanning technique was used to capture and analyze shape features of ballasts bere. Based on the reconstructed results of ballast shape, a construction method of ballast discrete element model was proposed. Then, a ballast box numerical model with cyclic loading was established. The influence laws of ballast gradation on ballast bed dynamic settlement under high-speed and heavy-haul railway conditions were studied with the numerical model, the microscopic ballast bed settlement mechanism was analyzed as well. The results showed that the railway ballast bed has different degradation mechanisms under different operation conditions, the relative motion between ballasts is the main reason for the settlement of heavy-haul railway ballast bed; for high-speed railway, the settlement of ballast bed is influenced by the rotation of ballast particles as well. Thus, it was suggested that different railway conditions should adopt different ballast gradation curves in the design code.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第5期127-133,156,共8页
Journal of Vibration and Shock
基金
国家自然科学基金重点项目(U1234211)
国家自然科学基金面上项目(51578053
51578055)
中央高校基本科研业务费(C15RC00120)
北京市科技新星计划(XX2013012)
关键词
铁路有砟道床
道砟级配
离散元法
道床沉降
动力响应
railway ballast bed
ballast gradation
discrete element method
ballast bed degradation
dynamic re-sponse
