横风对货车通过高墩桥梁行车安全性的影响分析

在对国内外研究成果进行简要介绍和分析的基础上,本文按一系悬挂和变摩擦阻尼建立货车的动力计算模型;轮轨作用力采用Kalker的线性接触理论并按Vermeulen-Jnhnson的非线性理论对其进行修正的方法;作为车桥系统外部激励的抖振力的时域随机风荷载按Shinozuka理论进行模拟。以某高墩连续梁刚构桥为对象,对考虑横风作用时货车的行车安全性进行了对比分析。计算结果表明：在横风作用时,背风侧的脱轨系数和轮轨作用力增加,轮重减载率减小,迎风侧的脱轨系数和轮轨作用力有所减小,轮重减载率增加;与无风时相比,横风的作用将导致车辆的行车安全性较为不利,这一结论与文献2]的试验结果基本一致。

The Running Safety Analysis of Freight Trains Passing on the High Pier Bridge to Cross Wind Loads

On the basis of briefly introducing and analyzing the domestic and international research achievements, this paper presents a framework for performing the dynamic responses of freight trains passing on the bridge to cross wind loads . The central suspension and variable friction damping are used to represent the dynamical model of the freight train, the Kalker small linear creep theory and the Vermeulen-Jnhnson nonlinear contact theory are adopted to represent mutual forces between the wheel and rail. The buffeting acting on the vehicle and bridge is generated in the time domain using computer simulation techniques proposed by Shinozuka. This formulation is then applied to a real long-span frame bridge with high piers carrying a railway. The results demonstrate that under the cross wind load the derailment coefficient and the wheel/rail interactive force of the down wind side are increased, and the reduced rate of the wheel load is decreased; while the derailment coefficient and the wheel/rail interactive force of the up wind side are decreased, and the reduced rate of the wheel load is increased. The running safety of the vehicle to the cross wind load is to be relatively disadvantaged, this conclusion is basically consistent to the test result given in papaer2].