| Project/Area Number |
16380098
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学・森林工学
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| Research Institution | Niigata University |
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Principal Investigator |
KAWABE Hiroshi Niigata University, Institute of Science and Technology, Prof. (80126036)
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| Co-Investigator(Kenkyū-buntansha) |
GONDA Yutaka Niigata Univ., Institute of Science and Technology, Associate prof. (10303116)
HAYASHI Setsuo Mie Univ., Fac. of Bioresources, Prof. (50024584)
NUMAMOTO Shinya Mie Univ., Fac. of Bioresources, Associate prof. (60324555)
近藤 観慈 三重大学, 生物資源学部, 助教授 (60335148)
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| Project Period (FY) |
2004 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥16,350,000 (Direct Cost: ¥15,600,000、Indirect Cost: ¥750,000)
Fiscal Year 2007: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2006: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2005: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2004: ¥8,500,000 (Direct Cost: ¥8,500,000)
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| Keywords | Landslide / Observation and prediction of natural phenomena / Stress release / Gravitational creep / Buckling / Salt weathering / International information exchange / Taiwan / 素因 |
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| Research Abstract |
Changes in geographical features of a slope after failure and re-instabilization of the slope by those were investigated for two large-scale landslides -- the Chiu-fen-erh-shan and the Tsaoling -- triggered by the Chi-Chi earthquake in 1999 in Taiwan. Furthermore, the mid Niigata prefecture earthquake and the Noto-Hantou earthquake which occurred during the term of this project were targeted for this study, too.
1. For the Tsaoling landslide which has the record of landslides in the past 150 years, the clear correlation between estimated maximum acceleration and occurrence of landslide wasn't admitted. The occurrence of landslide can't be explained only by earthquake, that is, the influence of causative factors is suggested.
2. Trial calculations by a simple model show that there is a possibility of buckling fold by gravitational creep and the position of buckling fold is on the lower part of slope.
3. The buckling fold and erosion on the lower slope of both the landslides progress year a
… More
fter year. The GPS survey at the Tsaoling landslide showed the horizontal displacement of about 5cm/year on the central part of slope and 1cm/year on the lower part of slope and the upheaval of 1-2cm/year. The slope is instabilizing gradually.
4. Simple seismic exploration was carried out to investigate decrease in the ground strength by stress release. The tendency that an elastic wave speed was decreasing at the rate of 400-600m/s a year was found.
5. The distribution of landslides caused by the mid Niigata prefecture earthquake was analyzed by GIS. The area rate of landslides which appeared in the landslide topography was 5.26% and that on the non-landslide topography was 0.16%. This result shows that the occurrence of landslide by an earthquake is strongly controlled by the history of the ground and a landslide by an earthquake doesn't happen easily in a slope where a landslide hasn't occurred yet. This phenomenon is thought to concern the re-instabilization of a slope from which upper load is removed Less
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