多维地震作用下桥上CRTSⅢ型板式无砟轨道系统动力响应  

Dynamic response of the China Railway Track System Ⅲ slab track system on a bridge under multidimensional seismic actions

作　　者：张鹏飞[1] 蔡科 王承隆 雷晓燕[1] 陈华鹏 ZHANG PengFei;CAI Ke;WANG ChengLong;LEI XiaoYan;CHEN HuaPeng(State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,南昌330013

出　　处：《中国科学：技术科学》2024年第5期924-939,共16页Scientia Sinica(Technologica)

基　　金：国家重点研发计划(编号:2022YFB2602200);国家自然科学基金(批准号:52178425);2022年江西省科技专项(国家科技奖后备培育项目)(编号:20223AEI91004)资助项目。

摘　　要：为研究多维地震作用下桥上CRTSⅢ型板式无砟轨道系统的动力响应,基于有限元法和梁-轨-板相互作用原理,建立了桥上CRTSⅢ型板式无砟轨道无缝线路精细化空间模型,分析了El-Centro波与天津宁河波多维地震作用下系统的受力与变形规律及其影响因素.结果表明:与El-Centro波相比,天津宁河波对系统动力响应有显著的增强效应;多维地震作用下桥梁轨道结构将产生较大的纵横向位移,且结构所受的纵、竖、横向力均较单向地震作用时大;同一地震波下多维地震激励得到的轨道各结构纵向受力与位移响应分布规律与纵向地震激励时一致;钢轨应力曲线均关于跨中呈反对称分布;各层间构件受力与变形曲线均关于桥梁纵向呈轴对称分布;轨道板、自密实混凝土层、底座板纵向位移随桥跨数的增加呈阶梯增减变化,最大值出现于最中间跨桥,轨板相对位移在最右侧梁缝处达到最大,极易导致轨下胶垫窜出引发扣件失效,同时左侧桥台与相邻固定支座墩顶最大位移差值显著,增加了落梁风险;采用小阻力扣件能有效减小地震作用下钢轨、固定支座墩/台顶的受力,但会显著增加轨板纵向相对位移,建议桥上扣件纵向刚度大小取值不低于10 kN/组;为有效保证地震发生时桥上高速列车行车安全,同时各部件不至于产生较大的位移,建议桥上固定支座墩/台顶纵向刚度宜采用不低于1.0倍系数值.This study investigated the dynamic response characteristics of the China Railway Track System(CRTS)Ⅲ slab ballastless track system on bridges under multidimensional earthquakes.According to the finite element method and the beam-rail-slab interaction principle,we built a refined spatial coupling model of the CRTS II slab ballastless track seamless line on a bridge.The two common seismic waves,the El-Centro wave and the Tianjin Ninghe wave,were used to analyze the stress and deformation laws of the system under the coupling action of multidimensional earthquakes and to explore the influencing factors of the stress and deformation.The results showed that the bridge track structure featured larger longitudinal and lateral displacements under the action of multidimensional waves from the earthquakes and that the longitudinal,vertical,and lateral stresses in the structure were larger than those under the action of one-directional wave earthquakes.Moreover,the distributions of the responding longitudinal stress and the corresponding longitudinal displacements of the track structures induced by the earthquakes were the same under the multidimensional coupling seismic excitation and longitudinal seismic excitation.The distributions of longitudinal stress and the displacements of the track structures were the same under multidimensional seismic excitation and longitudinal seismic excitation of the same seismic wave.As for the midspan,the stress-distance graphs of the rail were all distributed antisymmetrically.The stress and deformation curves of the structures were distributed axially symmetrical for the longitudinal direction of the bridge.The displacement of the track slab,the concrete layer,and the base slab changed in a step-like manner with the increase or decrease in bridge spans,and the maximum values occurred in the middle of the model span.The relative displacements of the rail and track slab were maximum at the rightmost beam joint.The use of low-resistance fasteners can reduce the stress on the rails and th

关 键 词：地震荷载 CRTSⅢ型板式无砟轨道 桥上无缝线路 一致激励 动力响应 

分 类 号：U213.244[交通运输工程—道路与铁道工程] U211.9