Longitudinal resonance mechanism of a long-span cable-stayed railway bridge under moving loads
Lu Long1 Li Jianzhong2
1. Chengdu University of Technology, Chengdu 610059, China；
2. State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China
Abstract：Under the moving train loads, a cable-stayed railway bridge generally vibrates in different directions. The longitudinal vibration of the bridge deck induced by the vertical train loads may influence the stability of track bed and the usage of retractor devices, and may even affect the running safety and riding comfort of train. The longitudinal vibration mechanism of the cable-stayed bridge under moving loads is investigated by using the equivalent longitudinal loads. A formula for estimating the resonant speed of the cable-stayed bridge is developed. A long-span cable-stayed railway bridge is taken as an example to analyze the dynamic response of the bridge under moving loads at different speeds. The numerical results indicate that when the speed of the moving load approaches the resonant speed predicted by the formula, the longitudinal loading frequency excited by moving load approaches the first-order longitudinal natural vibration frequency of the bridge. Then, the longitudinal resonance of the cable-stayed bridge occurs and the dynamic responses of the deck and the towers increase significantly.
吕龙 李建中 . 移动荷载作用下大跨度铁路斜拉桥纵向共振机理[J]. 土木工程学报, 2018, 51(2): 81-87.
Lu Long Li Jianzhong . Longitudinal resonance mechanism of a long-span cable-stayed railway bridge under moving loads. 土木工程学报, 2018, 51(2): 81-87.
