大跨简支钢桁梁桥-轨道系统地震响应特性研究

发布时间：2018-06-17 00:15

本文选题：铁路桥梁 + 轨道工程　；参考：《铁道学报》2017年07期

【摘要】：客货共线铁路大跨简支钢桁梁桥具有跨度大、活载重等特点,本文以156m简支钢桁梁桥为例,建立考虑相邻桥梁、路基和梁轨间非线性滞回特性的大跨简支钢桁梁桥-轨道系统仿真模型,分析纵向行波效应和竖向地震作用下大跨简支钢桁梁桥-轨道系统动力响应特征,探讨震前温度变化对系统地震响应的影响规律。研究表明:行波效应使钢桁梁桁架轴力、梁端相对位移及钢轨应力显著增大,对大跨简支钢桁梁桥和桥上无缝线路的抗震均有不利影响,轨道结构的存在进一步增大钢桁梁桁架轴力响应;桁架轴力响应对视波速极为敏感;钢轨应力随视波速增大而逐渐减小,并趋于一致激励下响应;震前温度变化对轨道应力影响显著,应予以考虑;对本桥而言,与顺桥向激励相比,竖向激励下桁架最大轴力增大1.5倍(拉)和0.8倍(压),钢桁梁段钢轨应力最大值减小42%。
[Abstract]:The long span simply supported steel truss bridge of passenger and freight common railway has the characteristics of long span and live load. This paper takes 156m simply supported steel truss bridge as an example to establish the adjacent bridge. The simulation model of long-span simply supported steel truss bridge track system with nonlinear hysteretic characteristics between subgrade and beam rail is presented. The dynamic response characteristics of long span simply supported steel truss bridge track system under longitudinal traveling wave effect and vertical earthquake are analyzed. The influence of temperature change before earthquake on the seismic response of the system is discussed. The results show that the axial force of steel truss, the relative displacement of beam end and the stress of rail are significantly increased by traveling wave effect, which has an adverse effect on the seismic resistance of steel truss bridge with long span and jointless track on bridge. The existence of track structure further increases the axial force response of steel truss; the axial force response of truss is extremely sensitive to apparent wave velocity; the rail stress decreases gradually with the increase of apparent wave velocity and tends to respond under uniform excitation. For this bridge, the maximum axial force of truss under vertical excitation increases by 1.5 times (pull) and 0.8 times (compression), and the maximum rail stress of steel truss section is reduced by 42 times compared with that of the bridge under vertical excitation, because the influence of temperature change before earthquake on the track stress is significant, and the maximum axial force of the truss under vertical excitation is increased by 1.5 times and 0.8 times, respectively.
【作者单位】：中南大学土木工程学院;中铁工程设计咨询集团有限公司桥梁工程设计研究院;
【基金】：国家自然科学基金(51608542) 中国铁路总公司科技研究开发计划(2015G001-G) 高速铁路基础研究联合基金(U13342023)
【分类号】：U211.9;U442.55

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