Based on cracking inspection on an orthotropic steel bridge, stress behaviors and fatigue life at cutout detail are investigated through field measurement and multi-level FEM modelling. Research finds that fatigue cracks at cutout detail are highly related to wheel path. Biaxial compression at cutout detail implies high residual stress and it suffers severe out-of-plane distortion. Fatigue life can be evaluated based on category B with stress location 5 mm away from free edge of cutout. It is concluded that serious overweight trucks, significant stress concentration, too thin diaphragms, and poor finish condition jointly contribute to early cracking at cutout detail.

基于正交异性钢桥的裂缝检查，通过现场测量和多级有限元建模，研究了切口细节处的应力行为和疲劳寿命。研究发现，切口细节处的疲劳裂纹与轮迹高度相关。切口细节处的双轴压缩意味着较高的残余应力，并且会遭受严重的面外变形。疲劳寿命可以根据类别B进行评估，应力位置距切口的自由边缘5 mm。结论是，严重的超重卡车，明显的应力集中，隔膜太薄以及不良的表面状况共同导致切口细节处的早期开裂。