Loading test of four span continuous PC box girder bridge degraded by salt attack and its safety evaluation through monitoring

Abstract

Loading test was carried out at four span continuous PC box girder bridge degraded by deicing agent. The bridge was loaded up to 1900 kN with hydraulic jacks. Stiffness of bridge was reduced when the load reached 1200 kN. This trend was succesufully simulated by non-linear FE analysis in which long-term monitoring data was considered. However, experiment was lower than FE analysis with regard to cracking load at several segment boundaries. This result indicates that strain measurement is necessary in long-term monitoring to detect the signs of deterioration earlier. Therefore, we focused on optical fiber sensors that can measure strain distribution. Consequently, we developed estimation method for the crack position and crack width from optical fiber data.