大跨度斜拉桥在车辆动力加载作用下的振动响应计算与监测

大跨度斜拉桥形式多样，结构轻柔，动力响应明显。为研究车辆动力加载作用对大跨斜拉桥的影响，基于健康监测系统长期监测数据建立车辆-桥梁动力相互作用分析模型，并编写相应计算程序。以福州市青洲大桥为工程背景，对随机车流进行模拟，考虑不同车辆类型及随机车流动态加载作用，建立车辆-桥梁动力平衡微分方程，验证车桥耦合振动模型，计算不同工况下由车辆载重、车距、车速等汽车荷载引起的桥梁振动响应。研究结果表明：车辆载重是影响桥梁位移变化的重要因素；控制行车间距有利于控制桥梁位移；行驶车速的提升和车辆数量的增加会在一定程度上引起主梁振动响应的加剧。研究成果可为大跨度斜拉桥的结构设计以及安全运营提供参考。

Vibration Response Calculation and Monitoring of Long-span Cable-stayed Bridge under Vehicle Dynamic Loading Effect

Long-span cable-stayed bridge has various forms, soft structure, and obvious dynamic response. In order to study the influence of vehicle dynamic loading on the long-span cable-stayed bridge, a vehicle-bridge dynamic interaction analysis model was established based on the Health Monitoring System data, and the corresponding calculation program was written. The Qingzhou Bridge in Fuzhou was studied as an example, the random traffic flow was simulated. The vehicle-bridge dynamic equilibrium differential equation was established to verify the vehicle-bridge coupling model considering different vehicle types and the dynamic loading effect of random traffic flow. The bridge vibration responses caused by vehicle load, vehicle distance, and vehicle speed under different working conditions were calculated. The results show that bridge displacements are greatly affected by vehicle loads. The control of driving distance is conducive to controlling the bridge displacement. The vibration responses of the main beam will be aggravated by the increase in the driving speed and the number of vehicles. The research results can provide reference for the structural design safe operation of long-span cable-stayed bridges.