|
|
|
| EXPERIMENTAL STUDY ON CHARACTERISTICS AND MECHANISM
OF BRITTLE FAILURE OF GRANITE |
| ZHOU Hui，MENG Fanzhen，LIU Haitao，ZHANG Chuanqing，LU Jingjing，XU Rongchao |
| ( State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China) |
|
|
|
|
Abstract In order to study the characteristics and mechanism of brittle failure of granite，the triaxial compression tests under different confining pressures were conducted and the scanning electron microscopy(SEM) were carried out. The microscopic characteristics of failure surface and the brittle failure mechanisms were discussed. In the range of the confining pressures adopted in the experiment，the granite showed strong characteristics of brittle failure and had no brittle-ductile transition. In addition to the oblique shear failure fracture，a kind of Y-shaped failure surface also appeared. The brittle failure of granite is governed by the occurrence of the plastic deformation and the scope and extent of the plastic yielding during the pre-failure period. The different mineral compositions and microscopic structural differentiations are the internal mechanism of brittle failure. The magnitude and the speed of the stress drop during the post-failure period are the external manifestations of the intensity of the brittle failure of granite. The speed of post-failure stress drop is determined by the interconnecting speed of macroscopic fractures which depends on the energy accumulation in granite. Whether the macroscopic fractures are interconnected completely determines the magnitude of post-failure stress drop.
|
|
Received: 26 May 2014
|
|
|
|
| [1] MARTIN C D，READ R S，MARTINO J B. Observations of brittle failure around a circular test tunnel[J]. International Journal of Rock Mechanics and Mining Sciences，1997，34(7)：1 065–1 073.
[2] READ R S. Interpreting excavation-induced displacements around a tunnel in highly stressed granite[Ph. D. Thesis][D]. Winnipeg：University of Manitoba，1994.
[3] MARTIN C D. Seventeenth Canadian geotechnical colloquium：the effect of cohesion loss and stress path on brittle rock strength[J]. Canadian Geotechnical Journal，1997，34(5)：698–725.
[4] HAJIABDOLMAJIDA V，KAISER P K，MARTIN C D. Modeling brittle failure of rock[J]. International Journal of Rock Mechanics and Mining Sciences，2002，39(6)：731–741.
[5] MARTIN C D. Seventeenth Canadian geotechnical colloquium：the effect of cohesion loss and stress path on brittle rock strength[J]. Canadian Geotechnical Journal，1997，34(5)：698–725.
[6] 何满潮，苗金丽，李德建，等. 深部花岗岩试样岩爆过程试验研究[J]. 岩石力学与工程学报，2007，26(5)：865–876.(HE Manchao，MIAO Jinli，LI Dejian，et al. Experimental study on rockburst processes of granite specimen at great depth[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(5)：865–876.(in Chinese))
[7] 苗金丽，何满潮，李德建，等. 花岗岩应变岩爆声发射特征及微观断裂机制[J]. 岩石力学与工程学报，2009，28(8)：1 593–1 603.(MIAO Jinli，HE Manchao，LI Dejian，et al. Acoustic emission characteristics of granite under strain rockburst test and its micro-fracture mechanism[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(8)：1 593–1 603.(in Chinese))
[8] LAJTAI E Z. Microscopic fracture processes in a granite[J]. Rock Mechanics and Rock Engineering，1998，31(4)：237–250.
[9] 陈友晴. Westerly 花岗岩试样单轴压缩破坏瞬时微裂纹观察[J]. 岩石力学与工程学报，2008，27(12)：2 440–2 448.(CHEN Youqing. Observation of microcracks patterns in Westerly granite specimens stressed immediately before failure by uniaxial compressive loading[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(12)：2 440–2 448.(in Chinese))
[10] NISHIYAMA T，CHEN Y，KUSUDA H，et al. The examination of fracturing process subjected to triaxial compression test in Inada granite[J]. Engineering Geology，2002，66(3/4)：257–269.
[11] NISHIYAMA T，KUSUDA H. Identification of pore spaces and microcracks using fluorescent resins[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1994，31(4)：369–375.
[12] SPRUNT E，BRACE W F. Direct observation of microcavities in crystalline rocks[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1974，11(4)：139–150.
[13] 朱泽奇，盛 谦，冷先伦，等. 三峡花岗岩起裂机制研究[J]. 岩石力学与工程学报，2007，26(12)：2 570–2 575.(ZHU Zeqi，SHENG Qian，LENG Xianlun，et al. Study on crack initiation mechanism of three Gorges granite[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(12)：2 570–2 575.(in Chinese) )
[14] 刘小明，李焯芬. 岩石断口微观断裂机制分析与试验研究[J]. 岩石力学与工程学报，1997，16(6)：509–513.(LIU Xiaoming，LEE C F. Mircofailure mechanism analysis and test study for rock failure surface[J]. Chinese Journal of Rock Mechanics and Engineering，1997，16(6)：509–513.(in Chinese))
[15] 杨圣奇，苏承东，徐卫亚. 大理岩三轴压缩压缩下强度和变形特性的试验研究[J]. 岩土力学，2005，26(3)：475–478.(YANG Shengqi，SU Chengdong，XU Weiya. Experimental investigation on strength and deformation properties of marble under conventional triaxial compression[J]. Rock and Soil Mechanics，2005，26(3)：475–478.(in Chinese)) |
|
|
|
2014, Vol. 33 
