近距離地震動の空間変動と地盤-構造物の相互作用を考慮した桁間衝突に関する研究

2003 Fiscal Year Annual Research Report

• Project/Area Number: 15560404
• Research Institution: Okayama University
• Principal Investigator: CHOUW Nawawi 岡山大学, 環境理工学部, 助教授 (70274016)
• Co-Investigator(Kenkyū-buntansha): 廣瀬 壮一 東京工業大学, 大学院・情報理工学研究科, 教授 (00156712)
• Keywords: 近距離地震 / 構造物-基礎-地盤系の応答 / 地盤-構造物系の非線形応答 / 鋼桁橋の桁間衝突 / 地震動の空間変動 / 地盤-構造物の相互作用 / 落橋防止 / 桁間距離

Research Abstract

目的:
本研究は,近距離入力地震動の空間変動と地盤-構造物の相互作用の影響を考慮した鋼桁橋の桁間衝突の特性を明らかにし,その結果を橋梁の耐震設計に役立てることを目的とする三年間の研究であり、平成十五年度はその初年度にあたる.
平成十五年度は以下に示す.
a.地盤-構造物系の非線形モデル.
b.衝突モデル.
c.地震動の空間変動数値モデルの各数値モデルについてそれぞれの研究分担者がモデルの開発を担当し研究を進める.
本研究の主な結果は以下の通りである.
個々の橋脚において一様でない空間変動を有する地震動を受ける二つの隣接する橋梁フレームの衝突の解析を行い、空間変動を有する地震動が桁の衝突を避けるために必要な桁間距離に及ぼす影響を検討した。その結果、地震動の空間変動は桁間の衝突に有利に働く場合と不利に働く場合があることがわかった。また、解析したほとんど全ての場合において、地盤と構造物の相互作用を考慮すると、桁の衝突を避けるために必要な桁間距離を広げる結果となった。
もし隣接構造物が軟弱地盤にあり、構造物の固有振動数が互いに近かった場合、空間変動を有する地震動によって構造物の相対的な変位量は増幅し、結果として橋梁の破壊する可能性が増すことが明らかとなった。

Research Products

• [Publications] Chouw, N., Hao, H.: "Effect of simultaneous spatial near-source ground excitation and soil on the pounding response of bridge girders"Journal of Applied Mechanics. 6. 779-788 (2003)
• [Publications] Hong, H., Chouw, N.: "Pounding and SSI effects on bridge response to spatially varying ground motions"Proc.of the 40 years of European Earthquake Engineering, Skopje and Ohrid, Macedonia. 8 (2003)
• [Publications] Hashimoto, K., Chouw, N.: "Effect of 3D-SSI and component of near-source ground motions on structural response"Proc.of the 40 years of European Earthquake Engineering, Skopje and Ohrid, Macedonia. 8 (2003)
• [Publications] Naito, Y., Chouw, N.: "Measures for preventing secondary structures from uplift during near-source earthquakes"Proc.of the 40 years of European Earthquake Engineering, Skopje and Ohrid, Macedonia. 8 (2003)
• [Publications] Kukaras, D., Chouw, N.: "Study of the effects of near source earthquakes on the moment resisting frame"Proc.of the 40 years of European Earthquake Engineering, Skopje and Ohrid, Macedonia. 6 (2003)
• [Publications] Gorgulu, U., Chouw, N.: "Measures for reducing the effect of pounding between adjacent buildings during near-source earthquakes"Proc.of the 40 years of European Earthquake Engineering, Skopje and Ohrid, Macedonia. 7 (2003)
• [Publications] Hashimoto, K., Chouw, N.: "Dynamic behaviour of a three-dimensional frame structure on half-space during near-source earthquakes"International summer symposium, JSCE, Tokyo. 97-100 (2003)
• [Publications] Kukaras, D., Chouw, N.: "Study of the effect of near-source earthquakes on the response of RC-structures"International summer symposium, JSCE, Tokyo. 101-104 (2003)
• [Publications] Su, H., Chouw, N.: "Possible reduction measure for three-dimensional structures during near-source earthquakes"International summer symposium, JSCE, Tokyo. 105-108 (2003)
• [Publications] Gorgulu, U., Chouw, N.: "Viscous damper as a measure for reducing the effect of pounding between adjacent buildings during near-source earthquakes"International summer symposium, JSCE, Tokyo. 109-112 (2003)
• [Publications] Hao, H., Chouw, N.: "Characteristics of Near Source Earthquake Ground Motion and Their Effects on Structural Responses"Australian earthquake engineering society's annual conference, Melbourne, Australia. 5/1-5/7 (2003)
• [Publications] Hashimoto, K., Chouw, N.: "Investigation of the effect of Kobe earthquake on a three-dimensional soil-structure system"Journal of Earthquake Engineering. 27. 1-8 (2003)
• [Publications] Kukaras, D., Chouw, N.: "RC frame response to the strong Northridge near-source ground excitations"9^<th> Yugoslav and 3^<rd> international scientific conference on Planning, design, construction and renewal in the construction industry INDIS 2003, Novi Sad, Montenegro and Serbia. 8 (2003)
• [Publications] Gorgulu, U., Chouw, N.: "Mitigation of pounding effect on bridges during near-source earthquakes"9^<th> Yugoslav and 3^<rd> international scientific conference on Planning, design, construction and renewal in the construction industry INDIS 2003, Novi Sad, Montenegro and Serbia. 8 (2003)
• [Publications] Su, H., Taniguchi, T., Chouw, N.: "Bumpers for reducing the effect of pounding between bridge decks"Journal of the Faculty of Environmental Science and Technology, Okayama University. 9. 111-116 (2004)
• [Publications] Hao, H., Chouw, N., Brownjohn, J.M.W.: "Field measurement and analysis of roadway filtering on traffic-induced ground motions"11^<th> Int.conf.on soil dynamic and earthquake engineering and 3^<rd> int.conf.On earthquake geotechnical engineering, UC Berkeley, USA. 1. 196-203 (2004)
• [Publications] Chouw, N., Hao, H.: "Investigation of Soil-structure Interaction and Near-source Ground Motion Spatial Variation Effect on Pounding of Bridge Girders"11^<th> Int.conf.on soil dynamic and earthquake engineering and 3^<rd> int.conf.On earthquake geotechnical engineering, UC Berkeley, USA. 2. 726-733 (2004)
• [Publications] Nawrotzki, P., Chouw, N.: "Effectiveness of Tuned-mass Dampers in Reducing the Response of Soil-structure Systems to Near-source Earthquakes"11^<th> Int.conf.on soil dynamic and earthquake engineering and 3^<rd> int.conf.On earthquake geotechnical engineering, UC Berkeley, USA. 2. 882-888 (2004)