云桂铁路南盘江上承式铁路拱桥动力分析与验证

云桂铁路南盘江大桥为上承式混凝土拱桥,大桥建成后,相关单位利用动态检测方法获取了23t轴重货物列车和CRH2列车以不同速度通过该桥时桥梁结构的多项动力响应,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,以南盘江大桥为背景,采用MSC系列软件建立列车-轨道-桥梁动力学仿真模型,分别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,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。对比结果表明:大桥一阶横弯与竖弯频率计算值分别为0.30 Hz和0.576 Hz,与实测的横弯频率0.33 Hz、竖弯频率0.59 Hz接近;分别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南盘江大桥的动力响应,数值仿真计算和实车动态测试的结果接近。

Dynamic Analysis and Verification of Nanpanjiang Deck Arch Bridge on Kunming-Nanning Railway

Nanpanjiang Bridge on Kunming-Nanning Railway is a deck concrete arch bridge. After the completion of the bridge, dynamic detection method is employed to obtain multiple dynamic responses of the bridge structure when the 23 t axle load train and CRH2 train pass the bridge at different speeds, and the dynamic performances of the bridge are evaluated. In order to explore the simulation effect of the dynamic simulation analysis method, the Train-Track-Bridge dynamic simulation model is established by using MSC series software with reference to the Nanpanjiang Bridge. The track irregularity excitation of freight cars and multiple units is respectively based on the five-level spectrum of the United States and the low-interference spectrum of Germany. The dynamic response law of the bridge structure is obtained by simulating the whole process of the train crossing the bridge. The simulation results are compared with the measurements. The results show that the calculated frequencies of first-order transverse bending and vertical bending are 0.30 Hz and 0.576 Hz respectively, which are close to the measured transverse bending frequencies of 0.33 Hz and vertical bending frequencies of 0.59 Hz. The wave length and amplitude of the five-level spectrum of the United States and the low-interference spectrum of Germany can better simulate the dynamic responses of freight trains and EMUs passing through Nanpanjiang Bridge. The results of numerical calculation and real vehicle dynamic test are close to each other.