2001 Fiscal Year Final Research Report Summary
Fracture Mechanics for Heterogeneous Materials and its Application to Controlled Blasting and Splitting
| Project/Area Number |
12450408
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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 |
資源開発工学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KANEKO Katsuhiko Hokkaido Univ., Graduate School of Eng., Prof., 大学院・工学研究科, 教授 (20128268)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASI Hiroshi Tohoku Univ., Graduate School of Eng., Assoc. Prof., 大学院・工学研究科, 助教授 (90188045)
HIRATA Atsuo Soujyou Univ., Faculty of Eng., Prof., 工学部, 教授 (20279376)
YONEDA Tetsuro Hokkaido Univ., Graduate School of Eng., Prof., 大学院・工学研究科, 教授 (00002056)
KATO Masaji Hokkaido Univ., Graduate School of Eng., Inst., 大学院・工学研究科, 助手 (10250474)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Fracture mechanics / Rock fracture / Sub-critcal crack growth / Crack Propagation / Microscopic structure / Controlled blasting / Rock splitting / Homogeneous material |
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| Research Abstract |
Although the rock is generally considered to be a heterogeneous material, the rock is usually treated as a homogeneous material in the fracture mechanics. In this study, the influence of heterogeneity on the crack growth in rock was analyzed and discussed.
(1) Double-Torsion test was performed to investigate the anisotropy of subcritical crack growth behavior in granite that is a typically heterogeneous rock. The experimental results confirmed that subcritical crack growth in granite was anisotropic and depended on the direction of the crack growth. Furthermore, the geometry of crack path becomes smoother in the case that the crack propagates with lower stress level. These behavior and characteristics are caused by the oriented microcracks. From these results, it is concluded that the crack growth in heterogeneous rock takes place with lower fracture energy by linking of mierocracks existing nearby crack tip.
(2) Mineralogical examination, physical properties measurement and slake durability tests of some argillaceous clastic rocks have been carried out and it was made clear that the mineral composition and texture of rocks in addition to smectite mineralogy have a great influence in rock durability.
(3) A numerical simulation method based on the finite element method and fracture mechanics for heterogeneous rock was proposed. Analyzing fracture processes of rock splitting by the breaker and rock fragmentation in bench blasting, the mechanism of splitting and fragmentation were clarified.
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Research Products
(12 results)
