| Project/Area Number |
12650911
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 |
FUJII Yoshiaki Hokkaido Univ., Grad. School of Eng., Assoc. Prof., 大学院・工学研究科, 助教授 (70192309)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Temperature / Critical Extensile Strain / Uniaxial Compressive Strength / Indirect Tensile Strength / Stress Intensity Factor / Stress Corrosion Index / Rock / Double Torsion Test / 応力腐食指数 / 圧縮試験 / 白浜砂岩 / 稲田花崗岩 / ひずみ速度 / 活性化エネルギー |
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| Research Abstract |
Uniaxial compression, Brazilian, CB and double torsion tests were carried out for Inada granite and Shirahama sandstone in water under 0℃ to 80℃. The main purpose of this study was in order to clarify effects of temperature on critical extensile strain of rocks etc. Results are as follows.
For Inada granite, with temperature increase from 0℃ to 80℃ :
(1) Average uniaxial compressive strength decreased by 6% ;
(2) Average critical compressive strain decreased by 6% ;
(3) Average absolute value of critical extensile strain increased by 30% ;
(4) Average Young's modulus showed maximum value at 40℃. Young's modulus at 80℃ was 14% smaller than that at 0℃ ;
(5) Average Poisson's ratio decreased by 20% ;
(6) Average indirect tensile strength decreased by 16% ;
(7) Average stress intensity factor decreased by 26% ; and,
(8) Average stress corrosion index decreased by 50%.
For Shirahama sandstone :
(1) Average uniaxial compressive strength decreased by 10% ;
(2) Average critical compressive strain decreased by 13% ;
(3) Average absolute value of critical extensile strain decreased by 3% ;
(4) Average Young's modulus showed maximum value at 20℃. Young's modulus at 80℃ was 13% smaller than that at 0℃ ;
(5) Average Poisson's ratio decreased by 11% ;
(6) Average indirect tensile strength decreased by 14% ;
(7) Average stress intensity factor decreased by 11% ; and,
(8) Average stress corrosion index decreased by 20%.
Activation energy was estimated as around 220 kJ/mol and 80 kJ/mol for Inada granite and Shirahama sandstone, respectively from results of CB and DT tests. FEM analyzes showed that large thermal stresses due to difference in thermal expansion of minerals occurred for Inada granite and that thermal stress was absorbed by clay minerals in Shirahama sandstone case.
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