## 1 Introduction
[26] studied the initial crack propagation characteristics and the initial angle effect of the inside weld in both-side-welded U-rib by using FRANC3D-ANSYS, and a fitting formula for the initial crack-growth effective angle range was derived. The initial crack angle of the inside weld toe of the U-rib was found to mainly affect the fatigue-life distribution of the structure at the crack growth stage, and the cracks with larger initial angles enter unstable propagation relatively quickly. [PERSON] et al. [27] investigated the fatigue life of structural details in the double side of a tanker ship by employing the spectral fatigue analysis approach, and the stochastic environmental loads were derived based on 3D diffraction theory in the frequency domain and then mapped with a structural finite-element model for the ship hull. The stress response for the considered details was extracted from the finite element analysis and the accumulated damage was estimated by Palmgren-Miner's rule. The reduction of the hull girder section modulus and the deterioration in fatigue strength due to corrosion were taken into account, and the influences of different wave scatter diagrams, the reduction of hull girder section modulus, the stress concentration factor, the free corrosion S-N curve, wave direction, wave spectrum, and the operational profile on the accumulated fatigue damage were also investigated. [PERSON] and [PERSON] [28] performed a realistic fatigue-life estimation of offshore wind turbine (OWT) monopile using the operational service loads recorded by online monitoring systems. Fatigue damage analysis was conducted at the circumferential weld joints using the finite element (FE) method by considering the geometrical and material property discontinuities, and the global-local modeling of the OWT was performed in as-welded condition to capture the local stress range for the weld toe. The S-N fatigue design approach and maximum stress range for the weld toe were used to determine the fatigue-crack-initiation life in monopiles, and the results from the proposed approach show that a realistic life assessment of monopile structures can be performed by accounting for the geometrical effects at the circumferential welds. Until now, the fatigue life assessment of weathering steel structures is only applicable at the specimen level. Based on the fatigue-life assessment method of corroded weathering steel at the specimen level proposed by [PERSON] et al. [24; 25], this paper generalized the method to a weathering steel bridge which is in service, and the multi-scale refined finite-element model is established, the key fatigue details of a typical weathering-steel anchor box of a typical cable-stayed bridge is evaluated by the finite element method, the remaining fatigue life after corrosion of the fatigue details is predicted, and the fatigue life evaluation for the corroded weathering-steel bridge is realized. The generalized method makes up for the lack of a fatigue-life assessment method for corroded weathering steel bridges in service. However, since the investigated bridge in this paper has only been in service for a short period of time, it lacks data on the corrosion pits, and the shape and size of the initial cracks are all assumed, for scientific research purposes, to demonstrate the feasibility of the proposed method. The development laws of pitting corrosion will continue to be tracked, information about the corrosion pits measured on site will be incorporated into the proposed method, and the method will continue to be improved accordingly in future studies.