Fatigue Damage Study of Reinforced Concrete T-Beam Bridge Considering Bearing Defect

Vehicle load is one of the primary factors influencing fatigue damage in reinforced concrete beam bridges, and diseases of bearings will accelerate the fatigue damage of beam bridges, but most of the current studies only consider the influence of vehicle load on the fatigue damage of beam bridges. In order to evaluate the fatigue damage of T-beam bridges more comprehensively, a numerical analysis method for the entire fatigue damage process of T-beam bridges is proposed, which considers the impact of bearing diseases and vehicle loads. The research results indicate the following: (1) During the fatigue calculation process of the T-beam, the maximum tensile fatigue damage value grows rapidly in the early stages. The effects of different bearing diseases and severities on the T-beam are generally similar. In the mid-stage, the growth of the maximum tensile fatigue damage value slows down, and the deeper the bearing disease, the greater the impact on the T-beam. In the later stage, the damage value grows rapidly until failure. (2) The displacement of bearings leads to stress concentration in the beam and the steel plates of bearings. The larger the slippage amplitude, the greater the stress value, which leads to a shortened lifespan of the concrete beam. (3) Bearing maintenance should focus on the damage of the beam. If displacement of bearings occurs, measures should be taken as early as possible (preferably within the mid-stage, 10–65 years); otherwise, it will result in a significant decrease in the beam’s life.