浅谈大跨度人行桥舒适度评估与减振设计

Preliminary Analysis of Comfort Evaluation and Vibration Reduction Design of Long Span Footbridge

随着城市综合体和城市交通的发展,钢结构人行桥广泛应用在地铁与城市快速路周围。钢结构人行桥趋向轻柔、大跨、低阻尼,在综合环境外部激励作用下可能会引起人行桥的过大振动,主要是桥上人行荷载引起的人行桥振动以及桥下车辆和地铁通过产生的地面振动引起的人行桥振动。不合适的振动会影响桥上行人的舒适度以及结构安全,需要结合人行桥的动力特性进行针对性的分析和减振设计。本文以上海某大跨度钢结构人行桥为例,建立舒适度评价标准,对人行荷载以及桥下车辆和地铁通过产生的地面振动引起的人行桥振动进行舒适度评估,进行相应的减振设计。结果表明,针对人行荷载采取的TMD减振措施以及针对地铁和车辆交通采取的桩-桥墩共同减振措施均可以满足本工程的舒适度设计要求。

With the development of HOPSAC and the urban communications,the steel footbridges have been widely used around subway and urban expressway. As the structure of steel footbridges tend to have less mass,large span and lower damping,the external load excitation in the integrated environment may lead to a large vibration of footbridges,which causes by two reasons： one is caused by pedestrian load,another is caused by subway and vehicle passing through the footbridge. Improper vibration influences the comfort of pedestrians on the footbridges and structural safety,so targeted analysis and vibration reduction design are necessary. This paper takes a large-span steel footbridge in Shanghai for example,vibration evaluation criteria were established,comfort evaluation and vibration reduction design caused by pedestrian-induced and subway vehicle-induced vibration were proposed. The result illustrates that the TMD method which reduce the pedestrian-induced vibration and the Pile-Pillar which reduce the subway vehicle-induced vibration are effective for vibration reduction design.