不同围压作用下煤-岩组合体破坏行为及强度特征

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...

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Bibliographic Details
Published in煤炭学报 Vol. 41; no. 11; pp. 2706 - 2713
Main Author 左建平 陈岩 张俊文 王金涛 孙运江 姜广辉
Format Journal Article
LanguageChinese
Published 2016
Subjects
岩石力学
峰值应变
峰值强度
残余强度
煤-岩组合体
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Summary: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。
Bibliography:ZUO Jian-plng1,2, CHEN Yan1 ,ZHANG Jun-wen3, WANG Jin-tao1, SUN Yun-jiang1,JIANG Guang-huil （ 1. School of Mechanics ＆ Civil Engineering, China University of Mining and Technology（Beijing） , Beijing 100083, China ; 2. State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology（Beijing） , Beijing 100083, China ;3. School of Mining Engineering, Heilongjiang Uni- versity of Science and Technology, Harbin 150022, China）
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 shea
ISSN:0253-9993