2019 Fiscal Year Final Research Report

Critical earthquake excitation method for multi-story elastic-plastic building structure and its application for earthquake-resistant design of building structure

Research Project

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Project/Area Number	19K21096
Project/Area Number (Other)	18H05930 (2018)
Research Category	Grant-in-Aid for Research Activity Start-up
Allocation Type	Multi-year Fund (2019) Single-year Grants (2018)
Review Section	0304:Architecture, building engineering, and related fields
Research Institution	Kyoto Institute of Technology
Principal Investigator	KOJIMA Kotaro 京都工芸繊維大学, デザイン・建築学系, 助教 (10822786)
Project Period (FY)	2018-08-24 – 2020-03-31
Keywords	極限地震応答 / 断層近傍地震動 / ダブルインパルス / トリプルインパルス / 多自由度弾塑性モデル / 不整形立体構造物 / 最悪地震動入力方向 / バイリニア＋スリップモデル
Outline of Final Research Achievements	After Hyogoken-Nanbu earthquake in 1995, the effects of pulse-like earthquake ground motions with a long period on structural responses have been investigated, and such pulse-like ground motions can cause large damages on building structures. When the equivalent natural period of the building structure coincides with the predominant period of the pulse-like ground motion, the deformation of the building structure is amplified. In this study, the efficient evaluation method has been proposed of the earthquake response of the multi-story elastic-plastic building structure in the critical case, where the equivalent natural period and the pulse period of the ground motion coincide. The simple estimation method of a critical response of the two-story wooden houses under the pulse-like ground motion was also suggested. Furthermore, the evaluation method of the worst input direction of the critical fling-step input was proposed for the three-dimensional irregular shaped building structures.
Free Research Field	建築構造・応用力学
Academic Significance and Societal Importance of the Research Achievements	弾塑性１自由度系の極限的なパルス性地震動に対する地震応答の閉形式解と静的漸増載荷解析に基づく１自由度系への縮約方法を用いて、多層建築構造物の弾塑性極限応答を評価する方法を提案している。これにより、従来の耐震設計でも用いられている解析結果を応用して多層建物が耐えることが出来る極限的地震動の最大地動速度を効率的に予測可能である。不整形建物を対象に、地震入力エネルギーを最大にする極限的な地震動の最悪入力方向を解明した。これにより、不確定性の高い地震動の周期特性や入力方向に対して安全性の高い建物の設計が可能になる。また、最悪な場合の地震応答を低減可能な立体的なオイルダンパーの最適配置を提案している。