紧急疏散工况下大跨度候车厅的人致振动响应分析

Analysis of Human-Induced Vibration Response in Large Span Waiting Hall under Emergency Evacuation Conditions

以高铁北京南站高架大跨度候车厅为对象,分析紧急疏散工况下的人群集体流动特征和可能的疏散路线;根据统计确定单人步态参数,并结合单人行走荷载,分别构建等效人群荷载模型、随机概率分布人群荷载模型和人群集度荷载模型;基于交通运输学领域的人群到达模型,结合北京南站实际的京沪高铁列车时刻表,确定人群荷载分布。运用ANSYS软件构建大跨度候车厅结构的有限元模型,针对紧急疏散不同时期的情况,施加相应的人群荷载激励时程,进行大跨度候车厅结构的人致振动响应分析。结果表明:在紧急疏散过程中,随着人群步频的加大和人群集度的增加,结构人致振动加速度响应显著增大,自由行走区的人致振动大于主候车区的人致振动,自由行走区和主候车区的人致振动加速度响应分别是疏散前的9.3倍和1.5倍;候车厅的人致振动加速度响应比疏散前大的结构面积达30.6%。因此,为保证大跨度候车厅结构的振动舒适性和安全性,在设计时需要考虑人群紧急疏散效应。

Taking the large span elevated waiting hall of Beijing South Railway Station for high speed rail- way as the research object, the collective flow characteristics of crowd and possible evacuation routines un- der emergency evacuation conditions were analyzed. Based on the statistics, individual gait parameters were determined. Combined with individual walking load, the equivalent crowd load model, stochastic probability distribution crowd load model and crowd collective degree load model was built respectively. According to the crowd arrival model in transportation domain and the actual train timetable of Beijing- Shanghai high speed railway in Beijing South Railway Station, the crowd load distribution was determined. The finite element model of large span waiting hall was built by using ANSYS software. In allusion to the emergency evacuation conditions of different stages, the corresponding crowd load stimulation time-history was applied to analyze the human-induced vibration response of large span waiting hall structure. The results show that the increase of stride frequency and crowd density during evacuation process will lead to significant increase in the human-induced vibration acceleration response of the structure. The human- induced vibration of free walking district is greater than that of main waiting district. The human-induced vibration acceleration response in free walking district and in main waiting district is 9.3 and 1.5 times respectively of that of before evacuation. The structure area with the increased human-induced vibration acceleration response than before evacuation in waiting hall is 30. 6%. Accordingly, emergency evacuation effect should be considered in the design to ensure the vibration comfort and safety of large span waiting hall structure.