大坡道桥上有砟道床纵向传力特性  

Longitudinal Force Transmission Characteristics of Ballasted Track Bed on Large Ramp Bridge

作　　者：景璞 肖杰灵[2] JING Pu;XIAO Jieling(Guangdong Yuedong Intercity Railway Co.Ltd.,Shantou Guangdong 515000,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]广东粤东城际铁路有限公司,广东汕头515000 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道建筑》2023年第8期33-39,共7页Railway Engineering

基　　金：四川省科技计划资助项目(2020YFG0125)。

摘　　要：在大坡道桥梁地段,受列车往复制动作用,轨排不断产生往复爬行,严重影响线路稳定与维护作业。为研究轨排与散体道床间的阻力特性及作用机制,基于通用离散元软件,建立桥上有砟道床-轨排相互作用节段模型,分析了轨排在往复制动作用下的纵向阻力、分阻力及阻力功的变化规律,并从道床密实度、轨排位移、枕底压力、颗粒运动等方面对道床的力学行为进行了解析。结果表明:不同制动荷载作用下道床阻力均呈强化趋势,制动位移越小,道床阻力达到稳定所需的制动周次越多;与空载条件相比,有载条件下列车往复制动时道床更快达到纵向稳定状态;基于分阻力解析,道床纵向强化主要由枕间道砟体致密化引起;往复制动会造成轨枕抬升,枕底压力减小,枕下支承刚度降低,几何不平顺增加及枕间道砟体动能剧增,出现道砟体流变现象。In the large ramp bridge section,due to the repeated braking of train,the track panel continuously produces repeated crawling,which seriously affects the stability and maintenance of the line.In order to study the resistance characteristics and action mechanism between the track panel and the loose track bed,a segment model of the interaction between the ballasted track bed and the track panel on the bridge was established based on the general discrete element software.The changes in longitudinal resistance,sub-resistance,and resistance work of the track panel under repeated braking were analyzed,and the mechanical behavior of the track bed was analyzed from the aspects of track bed density,track panel displacement,sleeper bottom pressure,and particle motion.The results show that under different braking loads,the resistance of the track bed shows a strengthening trend.The smaller the braking displacement,the more braking cycles are required for the track bed resistance to reach stability.Compared with the unloaded condition,the track bed reaches a longitudinal stable state faster when the train brakes back and forth under loaded conditions.Based on the analysis of sub-resistance,the longitudinal strengthening of the track bed is mainly caused by the densification of the ballast between the sleepers.Repeated braking can cause the sleeper to lift,the pressure at the bottom of the sleeper to decrease,the stiffness of the support under the sleeper to decrease,the geometric irregularity to increase,and the kinetic energy of the ballast between the sleepers to increase sharply,leading to the phenomenon of ballast rheology.

关 键 词：客货共线铁路 有砟道床 纵向阻力 离散元 往复制动 大坡道桥梁 分阻力 

分 类 号：U213.71[交通运输工程—道路与铁道工程]