| Recently in Japan, a huge number of infrastructures built during the high economic growth period are deteriorating due to aging. Focusing on steel bridges, damages and accidents caused by corrosion are increasingly reported. In addition, it is known that corrosion can become a crucial problem for steel bridges when found at diagonal members and connection areas, since it reduces the ultimate strength of a whole bridge system. Enabling to precisely evaluate the effect of corrosion at specific structural member on the ultimate strength of the whole bridge system leads to effective evaluation method for the deterioration of the structure; furthermore, a rational maintenance and management system of bridges. Thus, the ultimate goal of this research is to reveal the effect of corrosion damage at bridge member on the ultimate strength of whole bridge system. As a part of this goal, this study focuses on confirming the reproducibility of the ultimate strength of corroded diagonal member using FEM analysis.Specimens used in this research are collected from a real steel truss bridge, which was demolished after 46 years in service mainly due to functional reasons. Specifically, we focused on four long column specimens of diagonal members and one upper chord member which was divided into three stub column specimens with box-type cross section. In addition, each specimen was simulated with different corroded state to assess its effect on the remaining strength of corroded members. Corrosion on all the surfaces of the specimens were precisely measured using 3D laser measurement device in order to confirm the corrosion state and to apply for FEM model. Finally, compression test of the specimens were conducted to clarify the ultimate condition of the corroded specimens.Analytical results showed good agreement with experimental results with less than ten percent of discrepancies in the ultimate strength for all specimens. |
