工程科学学报，第41卷，第1期：43-52,2019年1月 Chinese Journal of Engineering,Vol.41,No.I:43-52,January 2019 D0L:10.13374/j.issn2095-9389.2019.01.004;htp:/journals.ustb.edu.cm 预制裂隙花岗岩的强度特征与破坏模式试验 郭奇峰12)区，武旭2)，蔡美峰12)，席迅2)，任奋华12)，苗胜军12) 1)北京科技大学土木与资源工程学院，北京1000832)北京科技大学金属矿山高效开采与安全教育部重点实验室，北京100083 ☒通信作者，E-mail:suoqifeng@(usth.cdu.cn 摘要为了探究单轴压缩条件下裂隙岩石的强度特性、裂纹起裂规律及破坏模式，采用水刀切割技术预制裂隙花岗岩试 件，利用GAW2000刚性试验机对单裂隙花岗岩试样进行单轴压缩试验.试验结果表明：与完整试样相比，裂隙岩石试样单轴 抗压强度明显降低，降低幅度与预制裂隙和外荷载方向的夹角B密切相关，β=75°时，强度最低，降幅达到84.5%，基于最大 畸变能准则计算了裂隙花岗岩的峰值抗压强度与裂隙倾角的关系，试验结果与数值解吻合：裂隙的存在改变了岩石的破坏模 式，裂纹起裂角随裂隙倾角的增加而单调增大，岩石试样的破坏模式由剪切破坏为主转变为张拉破坏占主导.真实裂隙岩石 试样的力学性质及裂纹起裂特征更准确地揭示了单裂隙花岗岩的强度变化规律和破坏模式，为岩土工程设计和巷道裂隙围 岩体的支护提供科学依据. 关键词预制裂隙花岗岩；单轴压缩：强度特征：起裂角：破坏模式 分类号TU458 Experiment on the strength characteristics and failure modes of granite with pre-existing cracks GUO Qi-feng,WU Xu,CAI Mei-feng),XI Xun,REN Fen-hua),MIAO Sheng-jun) 1)School of Civil and Resource Engineering.University of Science and Technology Beijing,Beijing 100083.China 2)Key Laboratory of High-Efficient Mining and Safety of Metal Mines Ministry of Education of China),University of Science and Technology Beijing, Beijing 100083.China Corresponding author,E-mail:guoqifeng@ustb.edu.en ABSTRACT Rock masses are typically anisotropic discontinuous materials composed of joints,fractures,and interlayers.Many in- stability and failure cases in geotechnical engineering have been induced by the expansion and transfixion of cracks in the rock masses. The mechanical properties and fracture characteristics of joints usually determine the bearing capacities and fracture modes of rocks.As such,the investigation of the crack initiation and expansion law,strength,and deformation characteristics of fractured rock masses has great significance.In this study,the rock samples investigated were taken from deep zones in the Sanshandao gold mine,where the surrounding rock masses are fractured and the maintenance costs of deep tunnels are very high.To investigate the mechanical behaviors of fractured rock masses,uniaxial compression experiments were conducted on granite samples with pre-existing cracks.First,cracks were generated in cylindrical rock samples by a water-jet cutter.Then,the rock samples with cracks and intact samples were compres- sively tested using a rigid testing machine (GAW2000)to determine their strength characteristics,crack initiation rules,and failure modes.The experimental results show that the uniaxial compressive strength (UCS)values of granite samples with pre-existing cracks are lower than those of intact samples,and the extent of the UCS reduction is closely related to B.i.e.,the angle between the pre-ex- isting crack and the direction of the external load.When B is 75,the UCS values of the samples are at their minimum,and the reduc- tion rate reaches 84.5%.These experimental results are in good agreement with the numerical solution of the maximum distortion ener- gy criterion.Pre-existing cracks change the failure modes of rocks.With an increase in the dip angle of a pre-existing crack,the crack 收稿日期：2018-07-26工程科学学报,第 41 卷,第 1 期:43鄄鄄52,2019 年 1 月 Chinese Journal of Engineering, Vol. 41, No. 1: 43鄄鄄52, January 2019 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2019. 01. 004; http: / / journals. ustb. edu. cn 预制裂隙花岗岩的强度特征与破坏模式试验 郭奇峰1,2) 苣 , 武 旭1,2) , 蔡美峰1,2) , 席 迅1,2) , 任奋华1,2) , 苗胜军1,2) 1) 北京科技大学土木与资源工程学院, 北京 100083 2) 北京科技大学金属矿山高效开采与安全教育部重点实验室, 北京 100083 苣 通信作者, E鄄mail: guoqifeng@ ustb. edu. cn 摘 要 为了探究单轴压缩条件下裂隙岩石的强度特性、裂纹起裂规律及破坏模式,采用水刀切割技术预制裂隙花岗岩试 件,利用 GAW2000 刚性试验机对单裂隙花岗岩试样进行单轴压缩试验. 试验结果表明:与完整试样相比,裂隙岩石试样单轴 抗压强度明显降低,降低幅度与预制裂隙和外荷载方向的夹角 茁 密切相关,茁 = 75毅时,强度最低,降幅达到 84. 5% ,基于最大 畸变能准则计算了裂隙花岗岩的峰值抗压强度与裂隙倾角的关系,试验结果与数值解吻合;裂隙的存在改变了岩石的破坏模 式,裂纹起裂角随裂隙倾角的增加而单调增大,岩石试样的破坏模式由剪切破坏为主转变为张拉破坏占主导. 真实裂隙岩石 试样的力学性质及裂纹起裂特征更准确地揭示了单裂隙花岗岩的强度变化规律和破坏模式,为岩土工程设计和巷道裂隙围 岩体的支护提供科学依据. 关键词 预制裂隙花岗岩; 单轴压缩; 强度特征; 起裂角; 破坏模式 分类号 TU458 收稿日期: 2018鄄鄄07鄄鄄26 Experiment on the strength characteristics and failure modes of granite with pre鄄existing cracks GUO Qi鄄feng 1,2) 苣 , WU Xu 1,2) , CAI Mei鄄feng 1,2) , XI Xun 1,2) , REN Fen鄄hua 1,2) , MIAO Sheng鄄jun 1,2) 1) School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Key Laboratory of High鄄Efficient Mining and Safety of Metal Mines (Ministry of Education of China), University of Science and Technology Beijing, Beijing 100083, China 苣 Corresponding author, E鄄mail: guoqifeng@ ustb. edu. cn ABSTRACT Rock masses are typically anisotropic discontinuous materials composed of joints, fractures, and interlayers. Many in鄄 stability and failure cases in geotechnical engineering have been induced by the expansion and transfixion of cracks in the rock masses. The mechanical properties and fracture characteristics of joints usually determine the bearing capacities and fracture modes of rocks. As such, the investigation of the crack initiation and expansion law, strength, and deformation characteristics of fractured rock masses has great significance. In this study, the rock samples investigated were taken from deep zones in the Sanshandao gold mine, where the surrounding rock masses are fractured and the maintenance costs of deep tunnels are very high. To investigate the mechanical behaviors of fractured rock masses, uniaxial compression experiments were conducted on granite samples with pre鄄existing cracks. First, cracks were generated in cylindrical rock samples by a water鄄jet cutter. Then, the rock samples with cracks and intact samples were compres鄄 sively tested using a rigid testing machine (GAW2000) to determine their strength characteristics, crack initiation rules, and failure modes. The experimental results show that the uniaxial compressive strength (UCS) values of granite samples with pre鄄existing cracks are lower than those of intact samples, and the extent of the UCS reduction is closely related to 茁, i. e. , the angle between the pre鄄ex鄄 isting crack and the direction of the external load. When 茁 is 75毅, the UCS values of the samples are at their minimum, and the reduc鄄 tion rate reaches 84郾 5% . These experimental results are in good agreement with the numerical solution of the maximum distortion ener鄄 gy criterion. Pre鄄existing cracks change the failure modes of rocks. With an increase in the dip angle of a pre鄄existing crack, the crack