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| EXPERIMENTAL STUDY OF TRIAXIAL MECHANICAL PROPERTIES
OF NATURALLY FISSURED RHYOLITE |
| ZHONG Zhibin1，DENG Ronggui1，LI Jia1，FU Xiaomin2 |
| (1. School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，Chengdu，Sichuan 610059，China) |
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Abstract A series of conventional triaxial tests with uniaxial preloading and triaxial tests with the confining pressure reducing were carried out on rhyolite specimens with natural micro fissures as the base of research on tardy failure of fissured surrounding rock of tunnel under the disturbance of excavation. Stress-strain curves of specimens with different micro fissures on two kinds of stress paths were obtained. The natural rhyolite specimens with micro fissures were found all to be remarkable brittle without a conspicuous yielding phase. The characteristics and distribution direction of micro fissures greatly affected the mechanical properties of specimens under two different stress paths. The micro fissures perpendicular to the maximum principal stress were difficult to extend leading to shear destruction and better mechanical behaviour. While if the initial dominating angle was small and the micro fissures linked dendritically with each other，macro tensile cracks would be formed in specimens，which weaken the mechanical behaviour of rocks. When the initial dominating angle of specimens with natural micro fissures was 46°in conventional triaxial tests，the mechanical properties were the worst. The lateral micro fissures were closed under uniaxial preloading. The strength，the elastic modulus and the deformation modulus of specimens measured with the conventional triaxial tests under pre-loading were increased due to the closing of fissures，Poisson?s ratios were basically unchanged and the characteristic of brittleness was more conspicuous.
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Received: 25 September 2013
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| [1] BOBET A，EINSTEIN H H. Fracture coalescence in rock-type materials under uniaxial and biaxial compression[J]. International Journal of Rock Mechanics and Mining Sciences，1998，35(7)：863–888.
[2] 黄明利，黄凯珠. 三维表面裂纹相互作用扩展贯通机制试验研究[J]. 岩石力学与工程学报，2007，26(9)：1 794–1 799.(HUANG Mingli，WONG R H C. Experimental study on propagation and coalescence mechanisms of 3D surface cracks[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(9)：1 794–1 799.(in Chinese))
[3] 李银平，杨春和. 裂纹几何特征对压剪复合断裂的影响分析[J]. 岩石力学与工程学报，2006，25(3)：462–466.(LI Yinping，YANG Chunhe. Influence of geinetric characteristics of pre-existing cracks on mixed mode fractures under compression-shear loading[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(3)：462–466.(in Chinese))
[4] 黄 达，黄润秋. 卸荷条件下裂隙岩体变形破坏及裂纹扩展演化的物理模型试验[J]. 岩石力学与工程学报，2010，29(3)：502–512. (HUANG Da，HUANG Runqiu. Physical model test on deformation failure and crack propagation evolvement of fissured rocks under unloading[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(3)：502–512.(in Chinese))
[5] 任建喜. 三轴压缩岩石损伤扩展细观机理及其本构模型[J]. 煤炭学报，2001，26(6)：578–583.(REN Jianxi. Rock meso-damage propagation law in the triaxial compression loading and its constitutive model[J]. Journal of China Coal Society，2001，26(6)：578–583.(in Chinese))
[6] 朱珍德，渠文平，蒋志坚. 岩石细观结构量化试验研究[J]. 岩石力学与工程学报，2007，26(7)：1 313–1 324.(ZHU Zhende，QU Wenping，JIANG Zhijian. Quantitative test study on mesostructure of rock[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(7)：1 313–1 324.(in Chinese))
[7] HORII H，NEMAT-NASSER S. Compression-induced microcrack growth in brittle solids：axial splitting and shear failure[J]. Journal of Geophysical Research：Solid Earth，1985，90(B4)：3 105–3 125.
[8] NEMAT-NASSER S，HORII H. Rock failure in compression[J]. International Journal of Engineering Science，1984，22(8)：999–1 011.
[9] 肖桃李，李新平，贾善坡. 深部单裂隙岩体结构面效应的三轴试验研究与力学分析[J]. 岩石力学与工程学报，2012，31(8)：1 666–1 673. (XIAO Taoli，LI Xinping，JIA Shanpo. Triaxial test research and mechanical analysis based on structure surface effect of deep rock mass with single fissure[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(8)：1 666–1 673.(in Chinese))
[10] 杨圣奇，温 森，李良权. 不同围压下断续预制裂纹粗晶大理岩变形和强度特性的试验研究[J]. 岩石力学与工程学报，2007，26(8)：1 572–1 587.(YANG Shengqi，WEN Sen，LI Liangquan. Experimental study on deformation and strength properties of coarse marble with discontinuous pre-existing cracks under different confining pressures[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(8)：1 572–1 587.(in Chinese))
[11] 王在泉，张黎明，孙 辉. 含天然节理灰岩加、卸荷力学特性试验研究[J]. 岩石力学与工程学报，2010，29(增1)：3 308–3 313.(WANG Zaiquan，ZHANG Liming，SUN Hui. Experimental research of mechanical properties of limestone containing natural joint under loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(Supp.1)：3 308–3 313.(in Chinese))
[12] 李宏哲，夏才初，王晓东，等. 含节理大理岩变形和强度特性的试验研究[J]. 岩石力学与工程学报，2008，27(10)：2 118–2 123.(LI Hongzhe，XIA Caichu，WANG Xiaodong，et al. Experimental study on deformation and strength properties of jointed marble specimens[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(10)：2 118–2 123.(in Chinese))
[13] YANG S Q，JING H W. Strength failure and crack coalescence behavior of brittle sandstone samples containing a single fissure under uniaxial compression[J]. International Journal of Fracture，2011，168(2)：227–250.
[14] LEE H，JEON S. An experimental and numerical study of fracture coalescence in pre-cracked specimens under uniaxial compression[J]. International Journal of Solids and Structures，2011，48(6)：979–999.
[15] 杨圣奇，戴永浩，韩立军，等. 断续预制裂隙脆性大理岩变形破坏特性单轴压缩试验研究[J]. 岩石力学与工程学报，2009，28(12)：2 391–2 404.(YANG Shengqi，DAI Yonghao，HAN Lijun，et al. Unixial compression experimental research on deformation and failure properties of brittle marble specimen with non-continuous pre-existing fissures[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(12)：2 391–2 404. (in Chinese))
[16] MEDHURST T P，BROWN E T. A study of the mechanical behaviour of coal for pillar design[J]. International Journal of Rock Mechanics and Mining Sciences，1998，35(8)：1 087–1 105.
[17] 邓荣贵，付小敏，邵 江，等. 泥巴山深埋特长隧道岩体工程问题研究[M]. 成都：西南交通大学出版社，2010：56–88.(DENG Ronggui，FU Xiaomin，SHAO Jiang，et al. Rock mass engineering research of deeply buried long tunnel in Niba mountain[M]. Chengdu：Southwest Jiaotong University Press，2010：56–88.(in Chinese))
[18] 邓 林，邓荣贵，付小敏，等. 泥巴山隧道流纹岩加卸围压力学特性研究[J]. 岩石力学与工程学报，2009，28(增1)：3 150–3 155. (DENG Lin，DENG Ronggui，FU Xiaomin，et al. Study on mechanical properties of rhyolite under loading and unloading conditions in Niba mountain tunnel[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(Supp.1)：3 150–3 155.(in Chinese))
[19] 中华人民共和国行业标准编写组. DL/T 5368—2007 水电水利工程岩石试验规程[S]. 北京：中国电力出版社，2007.(The Professional Standards Compilation Group of People?s Republic of China. DL/T 5368—2007 Code for rock tests of hydroelectric and water conservancy engineering[S]. Beijing：China Electric Power Press，2007.(in Chinese))
[20] ZHOU J W，XU W Y，YANG X G. A microcrack damage model for brittle rocks under uniaxial compression[J]. Mechanics Research Communications，2010，37(4)：399–405. |
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2014, Vol. 33 
