高速列车脉动风作用下车站人行天桥动力性能试验研究

我国高速铁路车站内人行天桥跨越股道连接各站台,当动车组高速通过正线时,列车周围将产生较大的气动力,会对跨越正线上方的人行天桥产生瞬间的推力和吸力,引起天桥结构横向、竖向振动,从而影响旅客通过天桥的舒适性和安全感。本文对国内外人行天桥振动标准进行归纳,分析京沈高速铁路阜新站内跨线人行天桥的自振特性和动车组通过时人行天桥的动力性能,研究人行天桥在脉动风激励作用下的振动特点、振动水平和振动分布规律,为我国高速铁路人行天桥振动舒适度限值的制订提供技术支持。研究结果表明:高速铁路人行天桥竖向振动加速度参考限值为1. 0 m/s2,横向振动加速度参考限值为0. 3 m/s2;列车行车速度大于300 km/h时,天桥跨中桥面中心区域竖向加速度超过参考限值。建议列车速度大于300 km/h时通过增大高速铁路跨线人行天桥竖向刚度、阻尼等方法减小其竖向振动,并采取优化天桥外形、增大天桥高度等方法减小脉动风的影响。

Experimental Study on Dynamic Performance of Railway Pedestrian Overpass Under High Speed Train Fluctuating Wind Action

Pedestrian overpasses on high speed railway stations connect the platforms across the stock rails.When the EMU passes through the main line at high speed,there will be a large aerodynamic force around the train,which will generate transient thrust and suction on the pedestrian overpass over the main line,causing the horizontal and vertical vibration of pedestrian overpass structure,thus affecting the comfortness and the security of passengers passing through.The vibration standards of pedestrian overpass at home and abroad were summarized in this paper,the natural vibration characteristics of pedestrian overpass in Fuxin Station of Beijing-Shenyang high speed railway and the dynamic performance of pedestrian overpass while EMU passing were analyzed.The vibration characteristics,vibration level and vibration distribution law of pedestrian overpass under fluctuatin g wind excitation were studied,which could provide technical supports for the vibration comfortness standards of pedestrian overpass on high speed railway in China.The analysis results show that the reference limit of vertical vibration acceleration and transverse vibration acceleration of high speed railway pedestrian overpass is 1.0 m/s^2 and 0.3 m/s^2 respectively.When the train speed is greater than 300 km/h,the vertical acceleration of central area of the mid-span pedestrian overpass deck exceeds the reference limit.It is suggested that the pedestrian overpass on high speed railway with speed greater than 300 km/h should increase the vertical stiffness and damping to reduce the vertical vibration of pedestrian overpass.Methods such as optimizing the shape of pedestrian overpass and increasing the height of pedestrian overpass should be adopted to reduce the inf luence of fluctuating wind.