桥上双块式无砟轨道道床板防裂优化设计研究  

Research on the Anti-cracking Optimization Design of Bed Slabs for Double-block Ballastless Track on Bridge

作　　者：曾志平[1] 申石文 涂勤明[2] 王卫东[3] 孟晓白 ZENG Zhiping;SHEN Shiwen;TU Qinming;WANG Weidong;MENG Xiaobai(Central South University, Changsha, Hunan 410075 , China;Guangzhou Metro Design & Research Institute Co. Ltd, Guangzhou, Guangdong 510010, China;Ministry of Education Key Laboratory of Heavy Haul Railway Engineering Structure, Central South University, Changsha, Hunan 410075 , China)

机构地区：[1]中南大学,长沙410075 [2]广州地铁设计研究院有限公司,广州510010 [3]中南大学重载铁路工程结构教育部重点实验室,长沙410075

出　　处：《铁道工程学报》2019年第7期19-26,共8页Journal of Railway Engineering Society

基　　金：中南大学自主探索创新项目(2019zzts416);高速铁路基础联合基金项目(U1734208);湖南省自然科学基金项目(2019JJ40384)

摘　　要：研究目的:受地理环境及天气等因素的影响,无砟轨道结构温度场分布不均且变化剧烈,在强烈且持续的温度荷载作用下,道床板易出现开裂现象。本文以京张高铁为背景,基于太阳辐射及边界换热理论,通过ABAQUS有限元软件建立桥上双块式无砟轨道结构温度场分析模型及顺序热应力耦合模型,探究温度荷载下道床板开裂机理及优化方法。研究结论:(1)道床板板中温度梯度波动幅度最大,正温度梯度可达+62. 32℃,负温度梯度可达到-31. 02℃;(2)道床板板中较易出现龟纹裂缝,在轨枕棱角接触处较易出现45°斜向裂缝,且裂缝较易发生横向发展,在道床板边缘处,较易发生垂向纵深裂纹;(3)增加抗裂斜筋后,道床板整体温度纵向应力最多减小5. 27%,效果不明显;(4)增加伸缩缝后的轨道结构道床板,温度应力的偏斜程度及离散程度均小于传统轨道结构,对于温度荷载的抵抗能力优于传统结构;(5)本研究成果可为完善双块式无砟轨道设计理论及养护维修方法提供技术支撑。Research purposes: Due to the influence of geographical environment and weather,the temperature field of ballastless track structure is unevenly distributed and changes drastically. Especially under strong and continuous temperature load,cracks will occur frequently in bed slab. So in order to explore the mechanism and optimization method of the bed slab cracking under temperature load,the ABAQUS finite element software is used to establish the temperature field analysis model and sequential thermal stress coupling model of the double-block ballastless track structure on the bridge,based on the theory of solar radiation and boundary heat transfer,with the background of Beijing-Zhangjiakou high speed railway.Research conclusions:( 1) The temperature gradient of the bed slab is the largest,the positive temperature gradient can reach + 62. 32 ℃,and the negative temperature gradient can reach-31. 02 ℃.( 2) Moire cracks are more likely to occur in the middle of the bed slab. 45° diagonal cracks are more likely to occur at the edges and corners of the sleeper block,and the cracks are more likely to develop laterally. Vertical deep cracks are likely to occur at the edge of the bed slab.( 3) After increasing the anti-cracking diagonal ribs,the longitudinal stress of the overall temperature of the bed slab is reduced by 5. 27% at most,and the effect is not obvious.( 4) After increasing the expansion joint for the bed slab of the track structure,the degree of deviation and dispersion of the temperature stress are smaller than the traditional track structure,and the resistance to temperature load is better than the traditional structure.( 5) The research results can provide important technical support for perfecting the double-block ballastless track design theory and maintenance and repair methods.

关 键 词：太阳辐射理论 有限元模型 温度应力 开裂机理 

分 类 号：U213.2[交通运输工程—道路与铁道工程]