2022 Fiscal Year Final Research Report
A study of 3-dimensional extension of microtremor exploration for determination of ground model to grasp earthquake landslide in advance
| Project/Area Number |
20K05028
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 25030:Disaster prevention engineering-related
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| Research Institution | Tottori University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
小野 祐輔 鳥取大学, 工学研究科, 教授 (00346082)
河野 勝宣 鳥取大学, 工学研究科, 准教授 (60640901)
西川 隼人 福井工業大学, 工学部, 教授 (60769371)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 微動探査 / 地震地すべり / 事前把握 / 地盤構造 / 地盤震動特性 |
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| Outline of Final Research Achievements |
In this study, we proposed an efficient method to investigate the ground structure and strong ground motion characteristics by utilizing the microtremor exploration technique in an advanced way to construct a subsurface structure model and to determine the strong ground motion characteristics to understand seismic landslides in advance. In addition to microtremor surveys, the use of artificial source waveforms as an exploration technique was found to improve the accuracy of subsurface structure estimation. The application of this technique to several landslide areas revealed that changes in microtremor characteristics corresponded to the locations of sudden changes in topography and ground structure, and that the seismic characteristics and deep subsurface structure could be estimated from seismic records in the landslide area. We also showed that Arias Intensity can be used in combination with microtremor survey results as an indicator for the advance prediction of seismic landslides.
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| Free Research Field |
地震工学
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| Academic Significance and Societal Importance of the Research Achievements |
地震地すべりの発生個所の多くでは，傾斜や凹凸のある基盤岩層の山体の上に火山噴出物が堆積する環境であり，それに関わる地盤の物理的特性等の情報が必要である．このような地域で，地震動の増幅特性を求めるには，特にS波速度構造の情報が必要不可欠であるが，その情報を得るためには，地質学的な考察，数カ所のサンプルの土質試験等の結果に頼らざるを得ない．そこで本研究では，微動探査をベースに，3次元的な傾斜地や不整形地盤構造での地盤構造調査法を検討し，地震動評価のための地盤構造モデルの構築と地盤震動特性の把握を行う．この研究成果は，地震地すべり地域での地震動評価と斜面崩壊の事前把握に繋がる．
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