2022 Fiscal Year Final Research Report

Seismic capacity of tower-like secondary structures standing on elevated viaducts and vision-based measurement of vibration characteristics of viaduct-tower structure systems

Research Project

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Project/Area Number	20H02231
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 22020:Structure engineering and earthquake engineering-related
Research Institution	Yokohama National University
Principal Investigator	FUJINO YOZO 横浜国立大学, 先端科学高等研究院, 名誉教授 (20111560)
Co-Investigator(Kenkyū-buntansha)	田村洋横浜国立大学, 大学院都市イノベーション研究院, 准教授 (10636434) 伊山潤東京大学, 大学院工学系研究科(工学部), 准教授 (30282495)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	構造工学 / 地震工学
Outline of Final Research Achievements	Many light poles on elevated highway bridge suffered from damage during 1995 Kobe earthquake, but their aseismic performance has not been studied systematically so far. In this research, first typical two types of light poles used in Tokyo Metro. Exp. Highway were tested under static cyclic loading and the ultimate performance of the light poles in the nonlinear range was captured. Based on the testing results, seismic performance of the light poles on typical elevated highway bridges under various levels of seismic design ground motion was numerically studied and their 3D behaviors were clarified. In order to apply this procedure to existing light poles, the natural frequency and damping of each light poles have to be known. A vision-based non-contact vibration measurement of the light poles on elevated highway bridges using motion magnification and dynamic mode decomposition methods is proposed and its high accuracy was proved.
Free Research Field	構造工学
Academic Significance and Societal Importance of the Research Achievements	本研究では，高架橋上の照明柱のうちレベル2 地震動により照明柱躯体の断面に生じる曲げモーメントが全塑性曲げモーメントを超えると予想される直線型ポールを対象とし，動的解析により地震応答特性を把握した．また，実物の照明柱を用いた単調載荷実験および正負交番載荷により照明柱の変形能および終局挙動を把握した．実験より得られた照明柱の非線形挙動と地震後の緊急輸送道路としての機能確保を考慮し，照明柱の限界状態と機能限界量から，限界状態を表す工学的指標を定め，高架橋上の照明柱の実用的な耐震照査法を提案した．併せて，高架橋上の既存の照明柱の固有振動数，減衰をビデオ画像から明らかにする非接触計測法を確立した．