2009 年駿河湾の地震における強震観測点周辺の状況と発生した地震動との対応性 Damage Investigation of Surroundings of the Seismic Stations in the 2009 Suruga Bay Earthquake and Correspondence of Damage to Bulidings with Strong Ground Motions

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Author(s)

    • 境 有紀 SAKAI Yuki
    • 筑波大学大学院システム情報工学研究科 University of Tsukuba, Graduate School of Systems and Information Eng.
    • 神田 和紘 KANDA Kazuhiro
    • 筑波大学大学院システム情報工学研究科 University of Tsukuba, Graduate School of Systems and Information Eng.

Abstract

2009 年駿河湾の地震を対象として,震度6 弱以上の全ての強震観測点と5 強を記録した一部の強震観測点周辺の被害調査を行った.その結果,屋根瓦の被害,外壁の損傷,内装材の落下といった被害は見られたが,いずれの観測点周辺でも,大破・全壊といった建物の大きな被害はなかった.しかしながら,木造建物の屋根瓦被害は数多く見られた.観測された強震記録の性質について検討した結果,そのほとんどが0.5 秒以下の極短周期が卓越した地震動で,建物の大きな被害と相関をもつ1-2 秒応答は小さく,このことが大きな震度にもかかわらず建物の大きな被害が生じなかった原因と考えられる.また,今回の地震で多く見られた屋根瓦被害について,定量的にデータを収集し,屋根瓦被害と相関を持つ地震動の周期帯について検討した.その結果,0.5 秒程度の弾性加速度応答が屋根瓦被害と高い相関をもつという結果になった.

We carried out damage investigation around the seismic stations where high JMA seismic intensity scales were recorded in the 2009 Suruga Bay Earthquake. We found some minor damage such as small damage to the wall or damaged roof tiles, but heavy damage to buildings was not found around all the seismic stations. However, we found many wooden houses with damaged roof tiles. We investigated the correspondence of strong ground motions with damage to buildings. Very short period below 0.5 sec. was dominated in most strong ground motions and the 1-2 sec. response which has close relationship with heavy damage to buildings was small, therefore, heavy damage to buildings was not found in spite of high JMA seismic intensity scale. We gathered quantitative data of damaged roof tiles and investigated relationship between the period region of strong ground motions and damaged roof tiles. We found that the period of about 0.5sec. of strong ground motions had close correlation with damage to roof tiles.

Journal

  • Journal of Japan Association for Earthquake Engineering

    Journal of Japan Association for Earthquake Engineering 10(4), 82-113, 2010

    JAPAN ASSOCIATION FOR EARTHQUAKE ENGINEERING

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