1998 Fiscal Year Final Research Report Summary
Synthetic study on the hillside disaster and stability of woods-land resulting from Earthquakes
| Project/Area Number |
08306008
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | Mie University |
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Principal Investigator |
HAYASHI Setsuo Bioresources Forestry Professor, 生物資源学部, 教授 (50024584)
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| Co-Investigator(Kenkyū-buntansha) |
TSUCHIYA Satoshi Shizuoka univ.Agri.Forestry Professor, 農学部, 教授 (60197720)
OKIMURA Takashi Kobe univ.Urban Safety Center Professor, 都市安全研究センター, 教授 (50031125)
OGAWA Sigeru Kyushu univ.Sgri.Forestry Professor, 農学部, 教授 (30037973)
NAKAMURA Hiroshi Tokyo Agi.& tech.univ.Forestry Professor, 農学部, 教授 (90242239)
KAWABE Hiroshi Bioresources Forestry Associateprofessor, 生物資源学部, 助教授 (80126036)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Earthquake disaster / Slope failure / Seismic ground motion / Amplification characteristics / Geological structure / Spectrum analysis / Debris flow / Disaster in old earthquakes |
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| Research Abstract |
First many slope collapses in the Rokko Mountains triggered by the 1995 Hyogo-ken Nanbu Earthquake. The correspondence to the distribution of the slope failurcs was tried to set frequency characteristics from the seismograms. 1) It is presumed that the maximum acceleration was about 300-400 gal and its predominant frequency was 1 Hz or less. 2) The distribution of the aftershocks corresponds well with that of the slope collapses. Therefore, it is possible that the distribution of breaking energy on the fault plane is reflected that of the slopecollapses.
Second the Kagoshima-ken Hokuseibu Earthquakes 1997 triggered many slope collapses in it's area. 1) The hillslopes underlain by granitic rocks are largely susceptible to slope collapses in comparison with those of sedimentary rocks. 2) The density of slope collapses, number of slope failures per 1km2, is 30.2 in the area underlain by granitic rocks and 7.6 in the area underlain by sedimentary rocks. The density of slope collapsesincreases with the height above sea level and the angle of slopes, In the area underlain by granitic rocks, however, many slope failures occurred at the lower height area and gentle slopes.
Third the purpose of the study is to improve the understanding of morphological and geological features of debris flows caused by earthquakes. Data of 24 slope movements which occurred in Japan after 1900 were collected from number of related literatures and investigated.
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