Fundamental Study on Compact Triaxial Compression Test for In-situ Rock Mass.
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Saga University|
ISIBASHI Koji Saga University, Faculty of Science and Engineering, Professor, 理工学部, 教授 (80137695)
|Project Period (FY)
1997 – 1998
Completed(Fiscal Year 1998)
|Budget Amount *help
¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1998 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1997 : ¥1,400,000 (Direct Cost : ¥1,400,000)
|Keywords||Rock Mass / In-situ Test / Triaxial Compression Test / Test Procedure / Test Equipment / Shear Strength / Angle Internal Friction / Stress-strain Curve / 内部摩察角 / 採石場 / 原位置岩盤 / 模型実験 / 破壊|
In 1997, prototype testing equipment of triaxial compression test for in-situ rock mass was manufactured. Model test considering application to in-situ rack mass was conducted using this equipment. The specimens, made of cement mortar with 15.4MPa of uniaxial compressive strength and rooted into concrete at bottom end, were cylinders of 100mm in diameter. The case that specimens have the single plane inclined with 60 degrees to the cylinder axis at middle part was also investigated.
In 1998, in-situ test was carried out at the quarry which located at Taku City and main rock formation is basalt. Confining pressure was applied to the coring specimen by water pressure transformed from nitrogen gas pressure. Reaction force for axial loading was given by heavy back foe with 0.8MN of self weight.
The following conclusions are drawn from a series of experimental research.
1) It was confirmed that the newly manufactured testing equipment has the functions previously programmed.
In the range of experiments, size effect about shear strength and internal frictional angle did not observed. The compact triaxial compression test gave about 5% less shear strength and internal frictional angle than the conventional triaxial compression test.
3) Triaxial compressive strength was strongly affected by the mechanical properties of discontinuity as well.
4) Improvement of sealing material was suggested, since calking material has not enough ability to seal the water pressure.
Only one specimen reached to the failure due to the shortage of reaction force. In order to cumulate the tested results and testing know-how, it will continue to be applied to the in-situ rock mass.
Research Output (8results)