铁路悬索桥疲劳最不利吊索分析方法

Analysis Method for the Most Unfavorable Fatigue of Hanger in Railway Suspension Bridge

铁路悬索桥活载在总荷载中所占比例较高,其应力幅相对公路桥更大,吊索更容易产生疲劳现象。国内对于悬索桥吊索疲劳相关理论分析较少,对于铁路悬索桥吊索的疲劳研究更是寥寥无几。本文根据我国铁路桥梁疲劳检算的设计规范和标准得出相应的疲劳荷载布载方式,结合悬索桥内力计算的特殊性,确定各吊索的疲劳设计竖向力;研究列车通过桥梁时各吊索点的纵向位移时程,确定纵向弯折的幅度。运用相应桥梁结构分析软件计算得出各吊索各部位相应荷载值,分析疲劳最不利吊索。

Live load in the proportion of the total load in railway suspension bridges is relatively high,the stress amplitude is higher compared with highway bridges,and fatigue phenomenon is more common in hunger. Domestic related theory analysis for fatigue of hunger in suspension bridges is rare,and the study for fatigue of hunger in railway suspension bridge is fewer. In this paper,fatigue load arrangement is achieved based on the railway bridge fatigue design specifications and standards. Combined with the particularity of the internal force calculation of suspension bridges,the vertical force for fatigue design of the hungers has been determined,and the extent of the longitudinal bending has been determined by confirming longitudinal displacement time history of the hunger while the vehicles passing through the bridge. By using the corresponding structure analysis software,the corresponding fatigue load of the hunger is calculated,and then the most unfavorable fatigue of hunger is analyzed.