This study is targeted for the estimation method for the remaining life of a corroded truss bridge based on the ultimate strength through one of case studies. The remaining life can be estimated by the corrosion limit which is defined as a corrosion state based on the assumption that the bridge collapse occurs when reaching the load required of the bridge performance. The deterioration curve of the corroded truss bridge is proposed by conducting nonlinear finite element analyses, in which the overall truss bridge is modeled as a rigid frame which consists of beam elements. According to the analytical results in this study, the overall bridge model at a non-corroded state has the safety factor as about 5 times of the design live load. In general, almost actual bridges have the concealed safety factors which were not considered in the design. It can be said that this is the reason why the bridges don’t collapse even if the severe corrosion occurs in members. However, corrosion progressions cause the strength reductions of bridges, then the bridges finally collapse when they reach the corrosion limit. Therefore, this study shows the fact that it is very important to evaluate the current safety of the actual bridges quantitatively by estimating the corrosion limit and remaining life.
Full Text (PDF)