南丘河大桥动力仿真分析与动态检测验证

南丘河大桥为一座高墩刚构桥,是云桂铁路全线的重点工程。大桥建成后,相关单位利用动态检测方法得到了23 t轴重货物列车和CRH2动车组以不同速度通过大桥时的多项动力响应,并评价了桥梁的动力性能。车桥动力仿真是目前特殊桥梁设计检算的重要手段,为探究动力仿真分析方法的模拟效果,采用MSC系列软件建立列车-桥动力学仿真模型,分别采用美国五级谱和德国低干扰谱作为货车和动车组的轨道不平顺激励,模拟列车过桥的全过程,并将仿真分析结果与实测结果进行对比验证,研究桥梁结构的动力响应规律。结果表明:大桥1阶横弯与竖弯频率计算值分别为0. 774,1. 880 Hz,与实测的横弯频率0. 83 Hz、竖弯频率1. 95 Hz接近;采用美国五级谱和德国低干扰谱,其波长和幅值能较好地模拟货物列车和动车组通过大桥的动力响应,计算值和实测值接近。

Dynamic Simulation Analysis and Test Verif ication of Nanqiuhe River Bridge

Nanqiuhe bridge is a continuous rigid frame bridge with high piers,which is a key project of Yunnan-Guangxi railway.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 23 t axle load train and CRH 2 EMU passed through the bridge at different speeds,and the dynamic performance of the bridge was evaluated.Vehicle-bridge dynamicsimulation is an important method of checking the design of special bridges at present.In order to explore the simulation effect of the dynamic simulation analysis method,the MSC series software was used to establish the dynamic analysis model of the bridge.The track irregularity excitation of the train and EMU was simulated by using the f ive-level spectrum of the United States and the low-interference spectrum of Germany respectively to simulate the whole process of train passing through the bridge.The simulation results were compared with the measured results to study the dynamic response of the bridge structure.The results show that the calculated frequencies of f irst-order transverse bending and vertical bending are 0.774 Hz and 1.880 Hz respectively,which are close to the measured transverse bending frequencies of 0.83 Hz and vertical bending frequencies of 1.95 Hz.The wave length and amplitude of the f ive-level spectrum of the United States and the low-interference spectrum of Germany can well simulate the dynamic response of train and CRH 2 EMU passing through the bridges.The calculated value is close to the measured value.