Abstract

One of the key issues on orthotropic steel deck (OSD) is the reduction of serviceability due to fatigue cracks even though the bridge still keeps a certain level of robustness itself, and accurately simulating crack growth process becomes crucial to evaluate the fatigue performance of OSDs. This paper proposes to measure the fatigue damage based on the two-stage crack growth model derived from experimental tests on the rib-to-deck welded joint of OSD. With the traffic data acquired by the weigh-in-motion system, the consideration of the near-threshold region, i.e., Stage I in the model, turns to be significant as the effect of the vehicle overload is shown more prominently. Thereupon, the way of fatigue damage evaluation is applied to each vehicle to quantify the severity of heavy vehicles with respect to the current status of the crack, and consequently to propose that the permit checking can be implemented in a more direct and dynamic way. The results can be valuable in the fatigue assessment that considers the remedial measures in the life-cycle of OSDs, e.g., the European Convention of Constructional Steelwork (ECCS) procedure, or in developing the guidance for the maintenance of specific bridges with OSDs.

摘要

正交异性钢甲板（OSD）上的关键问题之一是即使桥梁本身仍保持一定程度的坚固性，也会由于疲劳裂纹而降低使用性能，而准确模拟裂纹扩展过程对于评估OSD的疲劳性能至关重要。本文提出了基于两阶段裂纹扩展模型来测量疲劳损伤的模型，该模型是通过在OSD的肋对甲板焊接接头上进行的实验测试得出的。利用通过动态称重系统获取的交通数据，由于更加显着地显示了车辆超载的影响，因此考虑了接近阈值区域（即模型中的阶段I）变得非常重要。随即，将疲劳损伤评估方法应用于每辆车，以根据裂纹的当前状态量化重型车的严重程度，因此，建议可以更直接和动态的方式实施许可证检查。该结果对于考虑OSD生命周期中的补救措施的疲劳评估（例如，欧洲建筑钢结构公约（ECCS）程序）或为使用OSD的特定桥梁的维护指南的制定可能是有价值的。