大跨悬索桥钢箱梁焊缝重要性分级方法研究

Scaling Method for the Importance of Welds in Steel Box Girder in Long-span Suspension Bridges

为明确大跨悬索桥钢箱梁各焊缝的重要性,采用1-9标度法,对钢箱梁焊缝的重要性进行了评级。基于悬索桥钢箱梁焊缝位置特征、构造细节疲劳强度及焊缝特征分析,提出了钢箱梁控制截面、行车道荷载放大系数、焊缝疲劳强度及焊缝特征折减系数4类评定参数并赋值,建立了焊缝重要性评级方法。基于提出的评级方法分析了江阴大桥钢箱梁各类型焊缝的重要性等级,并与裂纹实际分布特征进行了对比。结果表明,基于所提出的评定方法得到的焊缝重要性评定结果与裂纹实际分布特征吻合较好,同时对斜拉桥钢箱梁焊缝重要性等级评定具有一定的借鉴意义。

To rate the importance of welds in the steel box girder of long span suspension bridge, the 1-9 scaling method was adopted. Based on the position feature, fatigue strength of fatigue details and characteristics of welds in steel box girder of suspension bridges, 4 evaluation parameters, including the control section of steel box girder, amplification factor of dynamical loads of traffic lanes, fatigue strength of welds and reduction coefficient of characteristics of welds, were proposed to develop the evaluation method for the importance of welds. With the proposed method, the importance hierarchy of welds of Jiangyin Yangtze River Bridge was calculated and compared with the distribution characteristics of detected fatigue cracks. The results show that the evaluating results obtained by the proposed method are in accordance with the distribution characteristics of detected fatigue cracks, which would be referentially significant for the importance evaluation of welds in cable-stayed bridges.