简支板桥在车辆荷载谱作用下的动力学分析

摘要

由自编程序 VLS( Vehicle Load Spectrum)构造随机车辆荷载谱，利用有限元程序将密集运行状态下的随机车辆荷载谱加载于钢筋混凝土简支空心板桥上，模拟桥梁在车辆荷载通过时的动力响应，分析了桥梁不同位置在车辆荷载作用下的反应，得出了位移时间历程曲线和加速度时间历程曲线。分析表明车辆荷载作用下桥梁整体振型复杂，最大位移不完全发生在跨中节点处，危险点存在于跨中一段范围内，且不同板块振动情况差别较大，中间板块由于边缘板块的约束作用而振动较弱。%The paper develops a Vehicle Load Chart program ( VLC program ) ,with the purpose of producing random vehicle load spectra. And with the help of finite-element program,the spectra in dense operation period is imposed to the reinforced-concrete simply-supported hallow slab bridge,to simulate its dynamic responses under vehicle loading. From the experiment,the reposes of the different sections of the bridge are analyzed and the patterns are concluded in the displacement-time curve and the acceleration-time curve. The results show that the analysis of the overall oscillation mode has found to be difficult,as the maximum value of displacement does not take place at the mid-span panel joints and the hazardous points can be found within certain section of the mid span. At the same time,the oscillations of different slabs display distinctively different patterns,while the mid slab oscillates at a fairly small amplitude due to the restraint of the edging slabs.