Health Monitoring–Based Assessment of Continuous Girder Bridge Reinforcement

This paper introduces a method of strengthening prestressed concrete continuous box-girder bridges with prestressed steel strands. Construction process monitoring, field load tests before and after reinforcement, and health monitoring after reinforcement were performed to verify the effectiveness of the external prestressed steel strand reinforcement method. During the construction monitoring process, the measured values of each tensioning step are basically consistent with the theoretical values, but the measured values are slightly less than the theoretical values. The results of the field load tests show that the bending strength and stiffness of the strengthened girder have been improved. During health monitoring, the strain value and deflection value data for some parts across the specified section were collected. According to the data, the strain and deflection values fluctuated within the specified limit, and the bridge was always in a safe state.