Abstract
The estimation of health for 7 span continuous rigid-frame bridge with prestressed concrete girder, having local damages, was conducted by nondestructive tests and load test. In this bridge, local damages of crack and flake-off, having 1.7 m in width and 0.75 m in height, were observed from the lower flange of middle span to the outside of web. The slack or rapture of PC bar was considered as cause of these damages, and the deterioration of load carrying capacity caused by damages was worried about. Therefore, the actual state of damage was grasped, the cause of damage was investigated, and then the estimation of health of bridge was carried out as a structure. From the results, it was confirmed that the damage had occurred for a coupler to strike into girder concrete at prestressing, then cracks had generated forward the outside of girder concrete, having a thick covering, by cleavability stress. However, it was confirmed as follows : PC bar was not ruptured. There was no difference between healthy span and damaged span in the performance of both dynamic deflection and vibration by using test vehicles, which satisfied with calculated value using the model of the third dimensional elements of alignment. This bridge has sufficient load carrying capacity for the opening.
