A Study on Impulsive Strong Ground Motion and its Observation
| Project/Area Number |
11650485
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
構造工学・地震工学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KIYONO Junji Dept. of Civil Eng., Kyoto Univ., Assoc. Prof., 工学研究科, 助教授 (00161597)
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| Co-Investigator(Kenkyū-buntansha) |
MORIKAWA Hitoshi Tokyo Institute of Technology, Assoc. Prof., 総合理工学研究科, 助教授 (60273463)
SAWADA Sumio D.P.R.I. Kyoto Univ., Assoc. Prof., 防災研究科, 助教授 (70187293)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Impulsive Wave / Fault Movement / High Frequency / Impulsive Force / Jumping Phenomena / FEM / Servo-type Accelerograph / Transducer-type Accelerograph / 兵庫県南部地震 / 上下動 / FEM / ジョイント要素 / 破壊モード / 跳躍現象 / 地震波 / 断層近傍 / 加速度波形 / インパルス / 地震観測 |
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| Research Abstract |
The 1995 Kobe earthquake is one of the worst disasters in recent Japan history, because of not only total number of casualties but also the fact that the earthquake struck a highly urbanized area in which many buildings, housings and infrastructures were concentrating. The cause of damage to the structures is generally explained by the action of large horizontal ground motion. But all unusual phenomena observed for bridge piers, steel frames, foundation structures, various rigid bodies and so on have not been made clear. Discussion from the view point of vertical ground motion which is applied as an impulsive load is not still sufficient. It is a fact, however, that the seismographs did not catch such impulsive accelerations of vertical component. In this paper, damage to structures due to the strong ground motion is surveyed first and the relation between damage and input ground motion is investigated in order to find the existence and the effect of the impulsive wave. Two accelerographs of a servo type and a transducer type are compared to check the sensitivity of high frequency component. FEM analysis by using a fault rupture model is carried out and the effect of nonlinear elements on the vertical ground motion is studied.
Main results obtained here is as follows :
(1) The existence of impulsive strong force can not denied according to many unusual phenomena observed in the 1955 Kobe earthquake.
(2) The amplitude of the up-down component of the earthquake becomes larger when the critical displacement of the fault is small and nonlinearity of the surrounding soil of the fault is considered.
(3) When the high frequency more than 20-50 Hz exists in the record, the servo-type accelerograph can not detect such component.
(4) The high frequency components have not observed in our observation site yet.
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Report
(4 results)
Research Products
(21 results)
