1999 Fiscal Year Final Research Report Summary
Slow Crack Growth in Rock Mass
| Project/Area Number |
10305075
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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 |
資源開発工学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
NAKASHIMA Iwao Graduate School of Eng., Hokkaido Univ., Prof., 大学院・工学研究科, 教授 (50001243)
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| Co-Investigator(Kenkyū-buntansha) |
HIRASHIMA Tuyoshi Graduate School of Eng., Hokkaido Univ., Associate Prof., 大学院・工学研究科, 助教授 (00175556)
KANEKO Katsuhiko Graduate School of Eng., Hokkaido Univ., Prof., 大学院・工学研究科, 教授 (20128268)
TUNEKAWA Masami Graduate School of Eng., Hokkaido Univ., Prof., 大学院・工学研究科, 教授 (40002026)
HIROYOSHI Naoki Graduate School of Eng., Hokkaido Univ., Res. Assoc., 大学院・工学研究科, 助手 (50250486)
YONEDA Tetsuro Graduate School of Eng., Hokkaido Univ., Associate Prof., 大学院・工学研究科, 助教授 (00002056)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Rock / Crack / Slow crack growth / Rock mass / Rock weathering / Permiability / Rock strength |
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| Research Abstract |
In this research project, a series of experimental and analytical studies on the mineralogical and the chemical properties of weathered rock, micro-crack distribution and permeability of rock, and crack propagation in rock, have been performed to clarify the mechanism of the slow crack growth in rock mass.
(1) A method to quantify the weathering of rock by using XFD and ATEM analyses was proposed and the mineralogical property of weathering rock was made clear.
(2) A method to evaluate the three dimensional orientation distribution of micro-cracks in rock was developed. It is pointed out that the anisotropy of rock permeability can be estimated by analyzing crack orientation distribution.
(3) A computer program to simulate the crack propagation in rock has been developed. Comparing the crack propagation processes in static and dynamic loading, a relation between the dynamic strength and the static one of rock is made clear.
(4) A mechanism of the giant rock fall occurred at the entrance of Toyohama tunnel has been analyzed. Analyzing the mineralogical property of smectite in the rock, it is pointed out that the long time strength of the rock may be reduced by the existence of smectite. From these result a theoretical model for slow crack propagation in rock mass was proposed.
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