不同围压作用下煤-岩组合体破坏行为及强度特征  

Failure behavior and strength characteristics of coal-rock combined body under different confining pressures

作　　者：左建平[1,2] 陈岩[1] 张俊文[3] 王金涛[1] 孙运江[1] 姜广辉[1] ZUO Jian-plng CHEN Yan ZHANG Jun-wen WANG Jin-tao SUN Yun-jiang JIANG Guang-huil(School of Mechanics ＆ Civil Engineering, China University of Mining and Technology（Beijing） , Beijing 100083, China State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology（Beijing） , Beijing 100083, China School of Mining Engineering, Heilongjiang Uni- versity of Science and Technology, Harbin 150022, China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [3]黑龙江科技大学矿业工程学院,黑龙江哈尔滨150022

出　　处：《煤炭学报》2016年第11期2706-2713,共8页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51374215;11572343);北京市科委重大科技成果转化落地培育资助项目(Z151100002815004)

摘　　要：通过MTS815试验机对钱家营矿煤-岩组合体进行常规三轴压缩试验。研究表明：围压作用下煤-岩组合体压密阶段较短,具有明显的线弹性及塑性屈服阶段,且随着围压的增大,峰后延性特征明显;根据峰值应变、弹性模量、破断角、强度的变化规律,10~15 MPa为组合体变形减缓的临界区间;煤样破坏主要以单斜面剪切破坏为主,并且个别岩体部分产生与煤样一致的剪切面,破断角处于14.1°~38.8°,均值为26.84°与理论破断角28.31°相差不大;随着围压的增大,残余强度有增高趋势,岩石强度衰减系数与之相反。围压从0~5 MPa,强度衰减系数降幅最大,体现出对围压的敏感性,随后围压继续升高,强度衰减系数呈线性递减;利用Hoek-Brown和广义HoekBrown准则对煤-岩组合体强度进行分析,讨论了适用于煤-岩组合体的参数m,s值。A testing system MTS 815 was used to carry out triaxial compression test for Qianjiaying coal-rock combined body. The results show that the consolidation stage is shorter and it apparently has a linear elastic stage and a plastic yield stage under the influence of confining pressure. Ductility of post-peak stage is much more apparent with the increase of confining pressure. Based on the change laws of peak strain,elastic modulus,rupture angle and strength,the threshold confining pressure of deformation is 10- 15 MPa. The failure mode of coal body is mainly shear failure,and some rock bodies have the same failure mode with coal body. The rupture angle is within the range of 14. 1°- 38. 8°and its average value is 26. 84° which has little difference with 28. 31° calculated using Coulomb strength criterion.Residual strength has an increasing trend with the increase of confining pressure while rock Dshas the opposite trend.From 0 to 5 MPa,the decreasing range of Dsis the largest which reflects the sensibility to confining pressure. Then,with the increase of confining pressure,Dsshows a linear decrease. Finally,the values of m,s in Hoek-Brown and generalized Hoek-Brown failure criterion are discussed.

关 键 词：岩石力学 煤-岩组合体 峰值应变 残余强度 峰值强度 

分 类 号：TD315[矿业工程—矿井建设]