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| EXPERIMENTAL STUDY ON EFFECT OF JOINTS WITH DIFFERENT LOCATIONS AND SIZES ON ROCK FAILURE |
| ZHOU Hui，MENG Fanzhen，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) |
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Abstract In order to study the effects of joint location and size on comprehensive shear strength of rock mass，cement mortar is selected as model material and specimens were prepared with prefabricated joints of the same size at different locations and with joints of various sizes at the same location，and shear tests were conducted under various normal stress of 3 different joints undulating angles. Experimental results indicate that shear strength increases with the increase of normal stress when the location and size of the joint are definite，and when the joint is located in the middle of the specimen，the shear strength and cohesion are the lowest，while largest when the joint is located at the back and fall in between them when located in the front of the specimen，but change law of the internal friction angle with different joint location is not obvious. When the joint location is definite，the longer the joint the lower the shear strength and cohesion. Moreover，shear strength of joint decreases linearly with increase of joint length. Effects of joint location and size on comprehensive shear strength of rock mass may be decided by both the strength parameters of joint and rock bridge and damage degradation of rock bridge. Position of joint should be considered when shear strength of in-situ jointed rock mass is estimated.
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| [1] 刘顺桂，刘海宁. 断续节理直剪试验与PFC2D数值模拟分析[J]. 岩石力学与工程学报，2008，27(9)：1 828–1 836.(LIU Shungui，LIU Haining. Direct shear tests and PFC2D numerical simulation of intermittent joints[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(9)：1 828–1 836.(in Chinese))
[2] 白世伟，任伟中，丰定祥，等. 平面应力条件下闭合断续节理岩体破坏机制及强度特性[J]. 岩石力学与工程学报，1999，18(6)：635–640.(BAI Shiwei，REN Weizhong，FENG Dingxiang，et al. Failure mechanism and strength properties of rock mass containing close intermittent joints under plane stress condition[J]. Chinese Journal of Rock Mechanics and Engineering，1999，18(6)：635–640.(in Chinese))
[3] 朱维申，陈卫忠，申 晋. 雁形裂纹扩展的模型试验及断裂力学机制研究[J]. 固体力学学报，1998，19(4)：355–360.(ZHU Weishen，CHEN Weizhong，SHEN Jin. Simulation experiment and fracture mechanism study of propagation of echelon pattern cracks[J]. Acta Mechanica Solida Sinica，1998，19(4)：355–360.(in Chinese))
[4] 张 平，李 宁，贺若兰，等. 不同应变速率下非贯通裂隙介质的力学特性研究[J]. 岩土工程学报，2006，28(6)：750–755.(ZHANG Ping，LI Ning，HE Ruolan，et al. Mechanical properties of fractured media containing intermittent fractures at different strain rates[J]. Chinese Journal of Geotechnical Engineering，2006，28(6)：750–755. (in Chinese))
[5] LAJAI E Z. Shear strength of weakness planes in rock[J]. International Journal of Rock Mechanics and Mining Sciences，1969，6(7)：499–515.
[6] LAJAI E Z. Strength of discontinuous rocks in directshear[J]. Geotchnique，1969，19(2)：218–233.
[7] SAVILABTI T，NORDLUND E，TEPHANSSON O. Shear box testing and modeling of joint bridge[C]// Rock joints：Proceedings of the International Symposium on Rock Joints. Rotterdam：A. A. Balkema，1990.
[8] 白世伟，任伟中，丰定祥，等. 共面闭合断续节理岩体强度特性直剪试验研究[J]. 岩土力学，1999，20(2)：10–16.(BAI Shiwei，REN Weizhong，FENG Dingxiang，et al. Research on the strength behaviour of rock containing coplanar close intermittent joints by direct shear test[J]. Rock and Soil Mechanics，1999，20(2)：10–16.(in Chinese))
[9] 任伟中，王庚荪，白世伟，等. 共面闭合断续节理岩体的直剪强度研究[J]. 岩石力学与工程学报，2003，22(10)：1 167–1 672.(REN Weizhong，WANG Gengsun，BAI Shiwei，et al. Strength behavior of rockmass containing coplanar close intermittent joints under direct shear condition[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(10)：1 167–1 672.(in Chinese))
[10] 张庆伦，赵延林，刘 杰，等. 剪切作用下类岩石断续裂纹岩桥破裂试验与数值分析[[J]. 矿业工程研究，2012，27(2)：31–36. (ZHANG Qinglun，ZHAO Yanlin，LIU Jie，et al. Experimental and simulation analysis of fracture of rock bridge under shear pressure[J]. Mineral Engineering Research，2012，27(2)：31–36.(in Chinese))
[11] 胡 波，张 楠，王思敬，等. 断续节理岩体模型试验及强度分析研究[J]. 地下空间与工程学报，2011，7(7)：657–665.(HU Bo，ZHANG Nan，WANG Sijing，et al. Model test and strength analysis research on intermittent joint rock mass[J]. Chinese Journal of Underground Space and Engineering，2011，7(7)：657–665.(in Chinese))
[12] 陈洪凯，唐红梅. 危岩主控结构面强度参数计算方法[J]. 工程地质学报，2008，16(1)：37–41.(CHEN Hongkai，TANG Hongmei. Method for calculating strength parameters of structural planes controlling the rock block stability[J]. Journal of Engineering Geology，2008，16(1)：37–41.(in Chinese))
[13] 刘远明，夏才初. 非贯通节理岩体直剪贯通模型和强度研究[J]. 岩土工程学报，2006，28(10)：1 242–1 247.(LIU Yuanming，XIA Caichu. Study on models and strength behavior of rock mass containing discontinuous joints[J]. Chinese Journal of Geotechnical Engineering，2006，28(10)：1 242–1 247.(in Chinese))
[14] 刘远明，夏才初. 共面闭合非贯通节理岩体贯通机制和破坏强度准则研究[J]. 岩石力学与工程学报，2006，25(10)：2 086–2 091.(LIU Yuanming，XIA Caichu. Study on models and strength behavior of rock mass containing discontinuous joints in direct shear[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(10)：2 086–2 091.(in Chinese))
[15] 唐志成，夏才初，刘远明. 岩桥渐进弱化的Jennings抗剪强度准则[J]. 岩土工程学报，2012，34(11)：2 093–2 099.(TANG Zhicheng，XIA Caichu，LIU Yuanming. Modified Jennings shear strength criterion based on mechanical weakening model of rock bridges[J]. Chinese Journal of Geotechnical Engineering，2012，34(11)：2 093– 2 099.(in Chinese))
[16] 夏才初，肖维民，丁增志. 非贯通节理Jennings强度准则的岩桥弱化和节理面起伏角修正[J]. 岩石力学与工程学报，2010，29(3)：485–492.(XIA Caichu，XIAO Weimin，DING Zengzhi. Modification of Jennings strength criterion for intermittent joints considering rock bridge weakening and joint surface undulating angle[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(3)：485–492.(in Chinese)) |
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2015, Vol. 34 
