Kemeng Ma
Large-span prestressed concrete continuous rigid frame bridges have increasingly become the favorite of designers due to their advantages such as fewer expansion joints on the deck, smooth deck surface, high bending stiffness in the longitudinal direction, high torsional stiffness in the transverse direction, and good seismic performance. However, due to the lack of foresight by designers during bridge design, the failure to promptly update old specifications, or construction errors during the construction process, the bridge structure may be overloaded, ultimately leading to excessive deflection in the main span of the continuous rigid frame bridge. This paper focuses on the characteristics of severe mid-span deflection in a specific continuous rigid frame bridge, analyzes the causes of deflection in continuous rigid frame bridges, and accurately establishes a structural damage model with deflection as the control index. Based on the mechanical characteristics of the structural damage model, combined with the reinforcement design scheme, a model of the structure after external prestressing reinforcement is established to analyze the reinforcement effect. After reinforcement, the bridge meets the requirements of the specifications, and the reinforcement effect is significant. The maximum deflection near the mid-span after reinforcement is -84.68 mm, which is an improvement of 22.88 mm or 27% compared to before reinforcement, indicating a remarkable reduction in deflection values. Received: 26.06.2025 Received in revised form: 12.06.202 Accepted: 02.07.2026