摘要
聚氨酯发泡道床是近年来提出的一种新型道床结构,该道床是在道砟空隙内填充聚氨酯柔性材料,与刚性的道砟颗粒相互作用而形成的一种轨道结构。针对其非连续、多种介质并存的结构特征,提出一种多元介质填充结构的离散元建模方法,首次实现离散元模型中刚柔介质的耦合。研究结果表明:与普通碎石道床相比,聚氨酯发泡道床具有良好的弹性,残余变形较小,有利于保持道床断面的几何形状;聚氨酯泡沫材料可有效减小道砟间的法向和切向接触力,从而有效减少道砟颗粒的挤压、摩擦作用;聚氨酯发泡道床道砟间接触力的分散性较小,受力比较均匀;聚氨酯发泡道床的刚度比普通碎石道床刚度减小40.67%~50.93%;聚氨酯发泡道床的最优固化宽度建议为80 cm,此时道床累积沉降最小、接触力最均匀。
Polyurethane foam ballast bed,a new ballast bed structure proposed in recent years,is filled with flexible polyurethane material in the ballast space and interacts with rigid ballast particles to form a track structure.In view of its discontinuous and multiple media coexisting structure characteristics,this paper proposed a discrete element modeling method for multi-media filled structures,which realized the coupling of rigid-flexible media in the discrete element model for the first time.The research results show that compared with ordinary ballast bed,the polyurethane foam ballast bed has good elasticity and less residual deformation,which is beneficial to maintain the geometry of the cross section of the ballast bed.The polyurethane foam material can effectively reduce the squeezing and friction effects of ballast particles by reducing the normal and tangential contact force between them.Compared with ordinary gravel track bed,the dispersion of contact force between the polyurethane foam track bed ballast is smaller with relatively uniform force.The stiffness of the polyurethane foam ballast bed is 40.67%~50.93%lower than that of the ordinary ballast bed.The optimal curing width of the polyurethane foam ballast bed is recommended to be 80cm.At this point,the track bed has the smallest cumulative settlement and the most uniform contact force.
作者
肖宏
吕亚鑫
迟义浩
XIAO Hong;Lü Yaxin;CHI Yihao(Beijing Key Laboratory of Railway Engineering,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第6期84-91,共8页
Journal of the China Railway Society
基金
国家自然科学基金(51578055)
高速铁路轨道技术国家重点实验室开放基金(2017YJ166)。
关键词
聚氨酯发泡道床
离散元模型
多元介质
刚柔耦合
力学特性
polyurethane foam ballast bed
discrete element model
multiple media
rigid-flexible coupling
mechanical propertie
