| Project/Area Number |
05452320
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
資源開発工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
SUGAWARA Katsuhiko Kumamoto University, Faculty of Engineering, Professor., 工学部, 教授 (60109668)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Tomoharu Kumamoto University, Faculty of Engineering, Research Associate., 工学部, 助手 (70207950)
KOIKE Katsuaki Kumamoto University, Faculty of Engineering, Research Associate., 工学部, 助手 (80205294)
OBARA Yuzo Kumamoto University, Faculty of Engineering, Associate Professor., 工学部, 助教授 (50135315)
KANEKO Katsuhiko Kumamoto University, Faculty of Engineering, Associate Professor., 工学部, 助教授 (20128268)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1993: ¥5,900,000 (Direct Cost: ¥5,900,000)
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| Keywords | Rock / Weathering / Strength deterioration / Fracture toughness / Stress corrosion / Freezing and thawing / 岩石強度劣化 / X線CTスキャナ / 弾性波速度 / 徴小硬度 |
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| Research Abstract |
Understanding of the composite action of natural environmental factors is indispensable for estimating the stability of rock and rock mass. However, there are unsolved problems for the effect of each factor. Especially, experimental results of the cyclic and cyclic heating are limited in spite of their importance. The present study on the durability of rock and its estimation method consists of three parts as follows :
1.Anisotropy effect on fracture toughness of rock.
To investigate the anisotropy effect on weathering of rock, the fracture toughness tests according to the suggested method of ISRM are performed, using three type of rock. It has been found out that the pre-existing crack within rock plays an important role in determing the fracture toughness, as well as the longitudinal wave velocity which is proportional to the fracture toughness.
2.Experimental study on stress corrosion of rock.
The influence of stress, strain rate, temperature and water vapor on the crack propagation in rock has been investigated by the uniaxial compressiontest in a vacuum chamber. The stress corrosion index has been precisely determined and the creep phenomena have been discussed as well as the long-term strength of rock.
3.Weathering of rock with freezing and thawing.
A cyclic test of freezing and thawing has been performed to make clear the weathering effect on the strength and the mechanical property of rock. In has been shown that the crack propagation in rock is depending upon the speed of freezing and/or thawing, and that a high speed freezing results the crack propagation normal to the free surface, but low speed freezing and thawing produce the cracks parallel to the free surface.
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