Development and application of inversion procedure of subsurface structure based on multiple utilization of observed microtremor on deployed traverse array measurement
| Project/Area Number |
16K06464
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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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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | University of Fukui |
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Principal Investigator |
Kojima Keisuke 福井大学, 学術研究院工学系部門, 教授 (40205381)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | 常時微動 / アレイ観測 / 拡張SPAC法 / 地下構造モデル / 逆解析 / 若狭地域 / 勝山盆地 / 測線展開アレイ観測 / H/Vスペクトル / Rayleigh波位相速度 / 地下構造 / 小浜平野 / 位相速度 / Ｓ波速度構造 / 微動 / 線状展開アレイ観測 / 表面波 / S波速度 / 盛土・斜面 |
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| Outline of Final Research Achievements |
The conventional spatial SPAC method requires at least four sets of simultaneous recording on concentric circles, so instrumental and personal resources have to be provided for the observations. To avoid this problem, I proposed a deploying traverse array observation procedure based on the assumption used in the two-sites SPAC method that wave fields are spatially and temporally stationary. By evaluating various information from the array observation simultaneously, the proposed procedure can estimate reliable underground structure with higher resolution. The proposed array observations were conducted in the Wakasa region and the Katsuyama basin to know S-wave structures of shallow and deep sedimentary layers down to the Mesozoic base rock. The validity of the estimated 3D-structures from the microtremor observations were confirmed by comparing with the density structure and with the existing seismic-reflection survey results.
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| Academic Significance and Societal Importance of the Research Achievements |
地震被害軽減のためには，詳細で信頼性の高い地下構造モデルに基づく予測が不可欠である．しかしながら，福井県のような地方では地下構造探査情報が少なく，微地形などに基づく概略的モデルを用いた地震被害予測が行われている現状がある．本研究で提案する微動観測法は，計器配置の自由度が高く，拡張SPAC法への適用性に優れている．このため，段丘のような逆転層がある地域においても，安定的にRayleigh波位相速度が算出でき，H/Vスペクトルの情報と併せることによって，信頼性の高い地下構造モデルが算出できることを確認した．また，本手法を若狭地域や勝山市に適用し，3次元地下構造モデルを提案し，一部を公表した．
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Report
(4 results)
Research Products
(9 results)
