Evaluation method of performance for bridges subjected to thermal history

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06478
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Osaka Institute of Technology
• Principal Investigator: Ohyama Osamu 大阪工業大学, 工学部, 教授 (70411410)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 橋梁火災 / 合成桁 / 剛性低下 / 低減係数

Outline of Final Research Achievements

Recently, the fire attack for bridges due to turning over accident of a tank lorry vehicle, incendiary fire and so on trends to increase in Japan and also in foreign countries. At present, the diagnosis and repair method of the existing bridge infrastructure damaged by fire have not been standardized yet in Japan. Therefore, to determine the passing propriety of composite girder bridges after fire, the author carried out the static loading test before and after fire.
From the fire test, 1) The temperature of the steel girder increase in descending order of the web, the lower flange and the upper flange. 2) The measured and thermal conductivity analysis, it was found that the analysis values of the upper and lower flanges and web was almost same as measured values. 3) The flexural rigidity of the composite girder reduced due to occur the clack in the concrete slab at the 680℃.

Free Research Field

橋梁工学，複合構造学

Academic Significance and Societal Importance of the Research Achievements

わが国において，火災による橋梁の力学特性を把握する研究を実施している研究機関は多くない．そこで，本研究の成果は，高温時および加熱自然冷却後の鋼の強度や加熱前後の合成桁の剛性低下を明らかにしている．
つまり，一般橋梁や高架橋が火災による熱影響を受けた後の通行可否を瞬時に判断するための評価手法を提案する基礎データを示しており，社会貢献に繋がると考えられる．