| Abstract: | Though the vibration of highway bridges is one of the primary reasons for deck cracking, it's often ignored by codes and researchers. Due to the excessive vibration and deck cracking, the SH-75 SB bridge over Wilson Creek in McKinney, Texas, was evaluated with non-destructive evaluation (NDE) and diagnostic load tests. Ground penetrating radar showed adequate cover on the top of the deck while impact echo revealed significant delamination of the top of the deck prevalent of the top of the girder lines. Results of the diagnostic load test indicated a significant loss of the composite action between the girders and the deck/panel system. A unique combined NDE and load test technique was used to rate the girder and the deck of the bridge which was never applied before. Besides, dynamic vibration testing was also conducted on the SB bridge to determine the maximum acceleration and natural frequency. The SB bridge exhibited significantly higher lateral and vertical accelerations and lower natural frequency due to loss of lateral stiffness. Finally, a calibrated finite element model was prepared in ABAQUS and several retrofitting and stiffening methods were studied to improve the composite action and reduce the vibration. Based on field data, a multiple linear regression equation was developed to predict corrosion rates. |