| Project/Area Number |
15K18109
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Akashi National College of Technology |
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Principal Investigator |
MIYOSHI Takao 明石工業高等専門学校, 都市システム工学科, 准教授 (40379136)
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | 圧延桁 / 桁端 / 腐食 / 断面欠損 / 残留応力 / 初期たわみ / 残存強度 / 圧延桁橋 / 桁端支点部 / 再配分挙動 / 変形挙動 / 再分配挙動 / 端支点 / 変形特性 |
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| Outline of Final Research Achievements |
This study investigated on re-distribution behavior of residual stress and deformation at H-rolled beam end under volume loss process due to corrosion. Also, collapse test using H-rolled beam end specimens which have different amount of volume loss were carried out by loading compression force on them.
As a result, this study found that additive deformation, which lead to decrease strength of steel structures, occurs because of unbalance of residual stress under volume loss process. Moreover, this study showed strength of H-rolled beam end with volume loss due to corrosion was able to evaluate conservatively using initial yield force, which is multiplication effective cross-sectional area by yield stress. However, effective cross-sectional area is calculated by deduction volume loss area from the cross-sectional area for designing end support portion of the girder specified in Japan Specifications for Highway Bridges. Also, yield stress is one of the material properties of steel.
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| Academic Significance and Societal Importance of the Research Achievements |
圧延桁橋は市町村管理の橋にも多用されているが，予算や技術者不足によって十分な維持管理が行われてこなかったものには，腐食に伴う断面欠損の発生事例が報告されており，その補修や架け替えの要否に関する合理的な判断基準が求められている．本研究では，実験を通じて断面欠損を持つ圧延桁端の強度を安全側で予測可能な方法を提案できた．また，断面欠損過程では残留応力の変化や変形が発生することを実験的に明らかにできた．しかし，本研究で対象とした断面欠損量では，断面欠損過程の残留応力の変化や変形が強度に及ぼす影響は小さいことが明らかとなった．
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