Modelling framework for dynamic interaction between multiple pedestrians and vertical vibrations of footbridges
Modelling framework for dynamic interaction between multiple pedestrians and vertical vibrations of footbridges
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DOI：
10.1016/j.jsv.2016.05.047
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发表时间：
2016-09
影响因子：
4.7
通讯作者：
F. Venuti;V. Racic;Alessandro Corbetta
中科院分区：
文献类型：
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作者：
F. Venuti;V. Racic;Alessandro Corbetta
经过15年的积极研究移动的人和土木工程结构之间的相互作用，仍然缺乏可靠的模型和适当的设计指南，由于多行人的人行桥的振动适用性。新一代模型迫切需要解决三个关键问题：行人与周围人和环境的“智能”交互、人体对空结构动力特性的影响以及行人步行载荷的主体间和主体内变异性。本文提出了一个建模框架的人-结构相互作用的垂直方向，解决所有这三个问题。该框架包括两个主要模型：（1）多行人交通的微观模型，模拟行人桥面上每个行人随时间变化的位置和速度，以及（2）行人桥和多个步行行人的耦合动力学模型。人行桥被建模为一个单自由度系统的动态特性的空置结构。每个步行的行人在一组或人群中建模为一个单自由度系统与相邻的随机垂直力，移动沿着人行天桥的轨迹和步态模式模拟的微观模型的行人交通。一系列的模拟振动响应的虚拟人行天桥，由于轻，中等和密集的行人交通的建议建模框架的性能说明。此外，威布尔分布被示出，以适应以及在加速度响应的局部峰值的概率密度函数。考虑到人群的固有随机性，这使得有可能确定超过所占用桥梁的任何给定加速度值的概率。
After 15 years of active research on the interaction between moving people and civil engineering structures, there is still a lack of reliable models and adequate design guidelines pertinent to vibration serviceability of footbridges due to multiple pedestrians. There are three key issues that a new generation of models should urgently address: pedestrian “intelligent” interaction with the surrounding people and environment, effect of human bodies on dynamic properties of unoccupied structure and inter-subject and intra-subject variability of pedestrian walking loads. This paper presents a modelling framework of human–structure interaction in the vertical direction which addresses all three issues. The framework comprises two main models: (1) a microscopic model of multiple pedestrian traffic that simulates time varying position and velocity of each individual pedestrian on the footbridge deck, and (2) a coupled dynamic model of a footbridge and multiple walking pedestrians. The footbridge is modelled as a SDOF system having the dynamic properties of the unoccupied structure. Each walking pedestrian in a group or crowd is modelled as a SDOF system with an adjacent stochastic vertical force that moves along the footbridge following the trajectory and the gait pattern simulated by the microscopic model of pedestrian traffic. Performance of the suggested modelling framework is illustrated by a series of simulated vibration responses of a virtual footbridge due to light, medium and dense pedestrian traffic. Moreover, the Weibull distribution is shown to fit well the probability density function of the local peaks in the acceleration response. Considering the inherent randomness of the crowd, this makes it possible to determine the probability of exceeding any given acceleration value of the occupied bridge.