Elucidation of epicenters and deep ground structure parameters that cause enormous damage to buildings

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K01312
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: University of Tsukuba
• Principal Investigator: Sakai Yuki 筑波大学, システム情報系, 教授 (10235129)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 深部地盤構造 / 震源 / 1-1.5秒 / 伝達関数 / 震源スペクトル

Outline of Final Research Achievements

The combination of the deep ground structure and the epicenter, which increases the 1-1.5 second component that causes the large damage to the building, was examined. As a result, it was found that the large 1-1.5 second component of the transfer function of the deep ground structure and the large 1-1.5 second component of the source spectrum were large.

Furthermore, it was found that the condition is that both of the deep ground structure and the epicenter are not "multiplication", but both are above a certain level. In other words, a large 1-1.5 second component appears when both the deep ground structure and the epicenter satisfy the conditions. Then, it was confirmed that the Uemachi fault of the Osaka plain satisfies the condition.

Free Research Field

構造動力学

Academic Significance and Societal Importance of the Research Achievements

本成果が意味することとしては，予め深部地盤構造と震源を調べておけば，どの断層でどの場所で建物の大きな被害に結びつく1-1.5秒の成分が出るかが予めある程度わかるということである．深部地盤構造の伝達関数も震源スペクトルも比較的簡単に計算できるので，全国の多くの活断層，あるいは，日本各地の深部地盤構造について計算を行うことができる．
具体的には，日本全国の深部地盤構造の伝達関数，および，大地震が想定される断層の震源スペクトルを計算することで，1-1.5秒成分が出る危険度マップのようなものが作成できることになり，防災上，非常に有益な情報を得ることができる．