大跨度钢桁梁斜拉桥风-车-桥系统耦合振动

Coupling vibration of wind-vehiche-bridge system for long-span steel truss cable-stayed bridge

以某大跨度公轨两用钢桁梁斜拉桥为工程背景,通过车桥组合节段模型风洞试验,测试了不同状态下车辆和桥梁各自的气动力系数,采用自主研发桥梁分析软件BANSYS,分析了不同风速、车速、车载状态下的风-车-桥系统,研究了车辆位置和双车交会对系统响应的影响。计算结果表明:当风速为25m.s-1,车速达到100km.h-1时,车辆的轮重减载率超过了行车安全性限值,且当车速达到120km.h-1时,车辆的竖向加速度超过了行车舒适性限值;风速较高时沿迎风侧轨道运行车辆的轮重减载率是系统的控制因素;车辆在空载状态下的各项响应均比在超员状态下的要大;由于迎风侧车的遮风效应,在双车交会开始和结束时车辆横向加速度出现突变。

A long-span road-rail steel truss cable-stayed bridge was taken as an engineering example, the aerodynamic coefficients of vehicle and bridge at different states were measured through wind tunnel test with the section models of vehicle and bridge. Wind-vehicle-bridge system was simulated at different wind speeds, vehicle speeds and vehicle load states by using the self-developed software BANSYS. The influences of vehicle position and two trains passing each other on the system were discussed. Computation result shows that wheel load reduction rate exceeds safety limit value when vehicle speed is up to 100 km ~ h-1 and wind speed is 25 m ~ s ~. When vehicle speed is up to 120 km ~ h 1, vehicle vertical acceleration exceeds comfortable limit value. When wind speed is higher, the wheel load reduction rate of vehicle running on windward side is the control factor for wind-vehicle-bridge system. The unloaded vehicle response is larger than overcrowded vehicle. Due to the wind shielding effect for windward side vehicle, transverse accelerations change suddenly at the beginning and ending of the process for two trains passing each other. 7 tabs, 5 figs, 14 refs.