上承式铁路拱桥动力分析与验证

沪昆客专北盘江大桥为上承式混凝土铁路拱桥。大桥建成后,相关单位利用动态检测方法获取了CRH380动车以不同速度通过大桥时的多项动力响应,并分析评价了桥梁的动力性能。为探究动力仿真分析方法的模拟效果,本文以该桥为背景,采用MSC系列软件建立列车-轨道-桥梁动力学仿真模型,采用德国低干扰谱作为动车组的轨道不平顺激励,模拟列车过桥的全过程,获得桥梁结构的动力响应规律,并将仿真分析结果与实测结果进行对比验证。分析结果表明：大桥一阶横弯与竖弯频率计算值分别为0.301Hz和0.588Hz,与实测的横弯频率0.29Hz、竖弯频率0.57Hz接近；采用德国低干扰谱,其波长和幅值能较好地模拟动车组通过大桥的动力响应,数值仿真计算和实车动态测试的结果接近。

Dynamic analysis and verification of deck railway arch bridge

Beipanjiang bridge on Shanghai-Kunming passenger line is a deck concrete railway arch bridge. After the completion of the bridge, the relevant units used the dynamic detection method to obtain multiple dynamic responses of the bridge structure when the CRH380 train passed the bridge at different speeds, and the dynamic performance of the bridge was evaluated. In order to explore the simulation effect of the dynamic simulation analysis method, taking the bridge as the background, the Train-Track-Bridge dynamic simulation model is established by using MSC series software. The track irregularity excitation of multiple units is based on the low-interference spectrum of Germany. The dynamic response law of the bridge structure was obtained by simulating the whole process of train crossing the bridge. The simulation results were compared with the measured results. The comparison results show that the calculated frequencies of first-order transverse bending and vertical bending are 0.301Hz and 0.588Hz respectively, which are close to the measured transverse bending frequencies of 0.29Hz and vertical bending frequencies of 0.57Hz, the wave length and amplitude of the low-interference spectrum of Germany can well simulate the dynamic response of CRH380 train passing through bridges. The results of numerical simulation and real vehicle dynamic test are close to each other.