随机人群荷载下大型火车站房大跨楼盖减振设计与分析

Design and analysis on vibration control of long-span floor in large station room under stochastic crowd-induced excitation

针对大型火车站房的大跨楼盖的振动舒适度问题,建立了某大型站房的整体有限元模型,采用Ritz向量法对结构进行了模态分析,研究了这类建筑中大跨楼盖的振动特性.以IABSE建议的单人步行激励为基础,考虑行人起步相位角随机分布,提出了楼盖随机人群荷载模拟方法,应用该方法对该大跨楼盖进行了人行荷载模拟,并通过多点输入和时程分析法对该楼盖进行了振动舒适度分析.总结已有的研究成果,根据大跨楼盖的振动特性,提出了大跨楼盖多重调谐质量阻尼器(MTMD)的减振设计方法,据此对楼盖进行了MTMD减振设计与分析.结果表明,利用该方法设计MTMD减振系统可以有效地控制大跨楼盖的竖向振动,最大衰减率达到72%,各工况下平均衰减率可达44%.

The vibration serviceability of long-span floors in large station rooms is studied.A finite element model of a large station room is established,and the modal properties of the structure are analyzed by the Ritz vector method;then the vibration properties of the long-span floors in this structure are studied.Based on the single person walking forces of IABSE（international association for bridge and structural engineering）,a new method to model stochastic crowd-induced loads is proposed considering the random distribution of the person＇s initial phase angle,and the human induced loads of the long-span floor are modeled by this method.Then the vibration serviceability of the floors is analyzed by a multi-support excitation and time history analysis method.According to the vibration characteristics of long-span floors,a design method for a long-span floor＇s multiple tuned mass dampers（MTMD） system is concluded from the existing researches,and a MTMD system in the floor is designed and analyzed by this method.The results shows that the MTMD system designed by this method can control the vertical vibration of the long-span floor effectively.The maximum attenuation rate under various working conditions is up to 72%.The average attenuation rate is about 44%.