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| INFLUENCE OF MICROCRACKS ON STRENGTH PARAMETERS OF ENGINEERING ROCK MASS |
| FAN Lei，ZHOU Huoming，ZHANG Yihu |
| (Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources，Yangtze River Scientific Research Institute，Wuhan，Hubei 430010，China) |
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Abstract By analyzing the tip stress field of compressive-shear microcrack，the initiation strength of rock mass containing crack is estimated. The results show that the initiation strength of rock mass has a relationship to the angle between microcrack and the orientation of the maximum principal stress and confining pressure. When the confining pressure increases，the initiation strength increases，but the initial angle will decreases. Only when the angle between the microcrack and the orientation of the maximum principal stress is in a certain range，the microcrack has an effect on the initiation strength of rock mass，and this range will reduce with the increasing confining pressure. Furthermore，the microcrack needs high applied force to keep propagating. Therefore，the failure of shallow engineering rock mass is mainly controlled by the penetrated cracks. The influence of microcracks on the mechanical behaviour of rock mass can be neglected when using the numerical methods.
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Received: 24 May 2010
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| [1] JAEGER J C. Shear failure of anisotropic rocks[J]. Geology Magazine，1960，97：65–72.
[2] HOEK E. Strength of jointed rock masses[J]. Geotechnique，1983，23(3)：187–223.
[3] JING L，HUDSON J A. Numerical methods in rock mechanics[J]. International Journal of Rock Mechanics and Mining Sciences，2002，39(4)：409–427.
[4] 朱焕春，RICHARD B，PATRICK A. 节理岩体数值计算方法及其应用(一)：方法与讨论[J]. 岩石力学与工程学报，2004，23(20)： 3 444–3 449.(ZHU Huanchun，RICHARD B，PATRICK A. Numerical methods and application for jointed rock mass，part 1：approaches and discussions[J]. Chinese Journal of Rock Mechanics and Engineering. 2004，23(20)：3 444–3 449.(in Chinese))
[5] GAHLE C，KUTTER H K. Breakage and shear behaviour of intermittent rock joints[J]. International Journal of Rock Mechanics and Mining Sciences，2003，40(5)：687–700.
[6] SHAYEA A I，NASER A. Crack propagation trajectories for rocks under mixed mode I–II fracture[J]. Engineering Geology，2005，81(1)：84–97.
[7] 陈卫忠，李术才，朱维申，等. 岩石裂纹扩展的实验与数值分析研究[J]. 岩石力学与工程学报，2003，22(1)：18–23.(CHEN Weizhong，LI Shucai，ZHU Weishen，et al. Experimental and numerical research on crack propagation in rock under compression[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(1)：18–23.(in Chinese))
[8] 徐靖南，朱维申，白世伟. 压剪应力作用下多裂隙岩体的力学特性——本构模型[J]. 岩土力学，1993，14(4)：1–15.(XU Jingnan，ZHU Weishen，BAI Shiwei. Multi-crack rock mass mechanical character under the state of compression-shearing—constitutive model[J]. Rock and Soil Mechanics，1993，14(4)：1–15.(in Chinese))
[9] 王元汉，徐 钺，谭国焕，等. 岩体断裂的破坏机制与计算模拟[J]. 岩石力学与工程学报，2000，19(4)：449–452.(WANG Yuanhan，TSUI Y，THAM L G，et al. Fracture mechanism and calculation of rock fracture[J]. Chinese Journal of Rock Mechanics and Engineering，2000，19(4)：449–452.(in Chinese))
[10] 王桂尧，孙宗颀，徐纪成. 岩石压剪断裂机制及强度准则的探讨[J]. 岩土工程学报，1996，18(4)：68–74.(WANG Guiyao，SUN Zongqi，XU Jicheng. Discussion on compression-shear fracture mechanism and strengthen criterion of rock[J]. Chinese Journal of Geotechnical Engineering，1996，18(4)：68–74.(in Chinese))
[11] 李建林，孙志宏. 节理岩体压剪断裂及其强度研究[J]. 岩石力学与工程学报，2000，19(4)：444–448.(LI Jianlin，SUN Zhihong. Study on crack and strength of joint rock under compression-shear stress[J]. Chinese Journal of Rock Mechanics and Engineering，2000，19(4)：444–448.(in Chinese))
[12] 何江达，张建海，范景伟. 霍克–布朗强度准则中m，s参数的断裂分析[J]. 岩石力学与工程学报，2001，20(4)：432–435.(HE Jiangda，ZHANG Jianhai，FAN Jingwei. Fracture analysis on the parameters m，s in Hoek-Brown strength criterion[J]. Chinese Journal of Rock Mechanics and Engineering，2001，20(4)：432–435.(in Chinese))
[13] 郑 炎，刘 杰，李建林，等. C-M和D-P屈服准则参数与岩石断裂韧度关系研究[J]. 华中科技大学学报：城市科学版，2006，23(增2)：30–32.(ZHENG Yan，LIU Jie，LI Jianlin，et al. Relation study between D-P and C-M failure criterion and rock fracture toughness[J]. Journal of Huazhong University of Science and Technology：Urban Science，2006，23(Supp.2)：30–32.(in Chinese))
[14] 周家文，徐卫亚，石 崇. 基于破坏准则的岩石压剪断裂判据研究[J]. 岩石力学与工程学报，2007，26(6)：1 194–1 201.(ZHOU Jiawen，XU Weiya，SHI Chong. Investigation on compression-shear fracture criterion of rock based on failure criteria[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(6)：1 194–1 201.(in Chinese))
[15] 李世愚，和泰名，尹祥础. 岩石断裂力学导论[M]. 合肥：中国科学技术大学出版社，2010：99–107.(LI Shiyu，HE Taiming，YIN Xiangchu. Introduction to rock fracture mechanics[M]. Hefei：University of Science and Technology of China Press，2010：99–107.(in Chinese)) |
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2011, Vol. 30 
