2018 Fiscal Year Final Research Report
A Study on a Seismic Hazard Assessment Method Considering the Amplification of Slightly Short-Period Pulse Ground Motion at the Basin Edge
| Project/Area Number |
16K06573
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Building structures/Materials
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
吾妻 崇 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 主任研究員 (00356370)
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
KAWASE Hiroshi 京都大学, 防災研究所, 特定教授 (30311856)
ICHIMURA Tsuyoshi 東京大学, 地震研究所, 准教授 (20333833)
NOZAWA Takashi 鹿島建設株式会社, 原子力部, 担当部長 (80463587)
|
|---|
| Research Collaborator |
DE MARTIN Florent
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Keywords | やや短周期パルス地震動 / 盆地端部 / 段差構造 / 増幅的干渉 / 地震危険度評価 / エッジ効果 / 微動水平上下スペクトル比 / 内陸地殻内地震 |
|---|
| Outline of Final Research Achievements |
This study was aimed to reveal the potential areas where slightly short-period pulse motion are amplified by the constructive interference due to the step structure of the bedrock and assess the seismic hazard of areas with danger of heavy damage.
As a result of strong motion estimation for earthquakes occurring on the Yokoto-bonchi-toen fault using an estimated subsurface structure of Yokote basin, area with high peak velocity in the western part of Yokote City was formed along the boundary of the basin, which showed the possibility of a “Damage Belt” to appear. On the other hand, a method to estimate the step structure of the bedrock from the microtremor Horizontal-to-Vertical spectral ratios was constructed and then a method was developed to estimate the location where slightly short-period motion will be amplified when there is a step structure of the bedrock, which was verified by comparing with the actual “Damage Belt” in the City of Kobe during the 1995 Kobe earthquake.
|
| Free Research Field |
地震工学
|
| Academic Significance and Societal Importance of the Research Achievements |
やや短周期パルス地震動は、周期1秒前後が卓越する揺れのことであり、1995年の阪神・淡路大震災は、震源から放出され、神戸市域の基盤の段差構造で増幅されたやや短周期パルス地震動により木造家屋などが倒壊したことが原因であった。以降の地震でもやや短周期パルス地震動が原因で建物被害が生じたが、やや短周期パルス地震動が強くなる箇所の事前予測の研究事例はほとんどない。本研究では、やや短周期パルス地震動が増幅的干渉する地域を推定出来る可能性を示した一方で、基盤の段差構造によって増幅的干渉をする位置を比較的簡易に推定する方法を開発した。これらの成果により、今後の地震対策に資する情報を提供できるものと考える。
|
