车辆冲击效应对钢桥面板疲劳评估的影响研究

Influence Study of Vehicle Impact Effect on the Fatigue Assessment for Steel Bridge Decks

为研究车辆冲击效应对钢桥面板疲劳评估的影响,建立连续钢箱梁桥节段有限元模型,采用连霍(连云港至霍尔果斯)高速公路7 d的动态称重(Weigh-in-Motion,WIM)数据开展典型细节疲劳评估,分析冲击系数对疲劳损伤评估结果的影响规律,并对现行规范的冲击系数适用性进行研究。结果表明,车辆冲击效应对钢桥面板疲劳评估结果影响显著,不同细节的冲击效应存在明显差异,其中纵肋-面板连接细节冲击效应影响最大、纵肋拼接细节最小;桥面铺装状况对钢桥面板冲击效应影响较大,铺装状况“次”时钢桥面板疲劳评估结果为铺装状况“优”的3.30~3.91倍。钢桥面板评估时应充分考虑车辆冲击效应的影响,根据铺装状况、细节类型选取合理的钢桥面板冲击系数。

In order to study the vehicle impact effect on the fatigue assessment for steel bridge decks,the segmental finite element model is built of a continuous steel box girder bridge,and 7-day Weigh-in-Motion(WIM)data of Lianyungang-to-Horgos Expressway is selected to carry out fatigue assessment of typical details.The influence law of impact factors on the fatigue assessment result is analyzed,and the applicability of impact factors in different current specifications is studied.Research results show that the vehicle impact effect has a significant influence on the fatigue assessment results of steel bridge decks.Obvious differences exist in impact effects of different details,the impact effect of rib-to-deck detail is the largest,and the rib-to-rib detail is the smallest.The bridge deck pavement condition has great influence on the impact effect of steel bridge deck,fatigue assessment result of“worse”pavement condition is 3.30-3.91 times of“excellent”pavement condition.The vehicle impact effect should be fully considered when the fatigue assessment is performed,and reasonable impact factors should be adopted according to pavement conditions and detail types.