冲击倾向煤破坏断口微观特征及其机理研究
|
摘要
运用扫描电镜观测了冲击倾向煤破坏断口的微观形貌,分析了煤体受载破坏断面的裂纹、孔隙等缺陷特征及裂纹扩展特征,探讨了煤样破坏裂纹扩展途径及其微观断裂机理.结果表明,冲击倾向煤内部含有大量的孔隙裂隙,在其受载破坏过程中,这些孔隙裂隙均充当了Griffith缺陷,促使大量新裂纹生成和煤样发生破坏.煤样中大量的尖锐孔隙及张性裂隙的微观断面特征表现出冲击倾向煤的脆性特征.由于煤的非均质性及煤样内部应力分布的非均衡性,其裂纹扩展也是不均匀、间歇式的,且裂纹的扩展路线也是曲折的,扩展过程中往往产生分岔、拐折等现象.孔隙、裂纹在应力作用下分岔、扩展、汇合贯通是导致煤体宏观断裂的直接原因.
Based on observation results of the micro-topography of impact trend coal fracture surface with SEM method,the characteristics of defect such as pores,cracks and crack propagation in fracture surface of coal samples were analyzed,and the crack growth route and micro-fracture mechanisms of the hard brittle coal were studied.The results show that there are plenty of pores and cracks in impact trend coal,and they act as Griffith defects in the fracture process of coal that advancing the growth of new cracks and fracture of coal samples.The microscopic characteristics of fracture section of plenty of acute pores and tensile cracks indicate the brittle characteristics of impact trend coal.The crack growth in coal is heterogeneous and intermittent for the heterogeneity and non-proportionality of coal structure,and the crack propagation path is flexuose with bifurcation and inflection.The direct reason of the macroscopic fracture of coal is the bifurcation,expand,confluence and connection of the cracks or pores under load.
Based on observation results of the micro-topography of impact trend coal fracture surface with SEM method,the characteristics of defect such as pores,cracks and crack propagation in fracture surface of coal samples were analyzed,and the crack growth route and micro-fracture mechanisms of the hard brittle coal were studied.The results show that there are plenty of pores and cracks in impact trend coal,and they act as Griffith defects in the fracture process of coal that advancing the growth of new cracks and fracture of coal samples.The microscopic characteristics of fracture section of plenty of acute pores and tensile cracks indicate the brittle characteristics of impact trend coal.The crack growth in coal is heterogeneous and intermittent for the heterogeneity and non-proportionality of coal structure,and the crack propagation path is flexuose with bifurcation and inflection.The direct reason of the macroscopic fracture of coal is the bifurcation,expand,confluence and connection of the cracks or pores under load.
引文
[1]傅雪海,秦勇,薛秀谦,等.煤储层孔、裂隙系统分形研究[J].中国矿业大学学报,2001,30(3):225-228.FU Xue-hai,QIN Yong,XUE Xiu-qian,et al.Re-search on fractals of pore and fracture-structure ofcoal reservoirs[J].Journal of China University ofMining&Technology,2001,30(3):225-228.
[2]张慧,李小彦,赫琦,等.中国煤的扫描电子显微镜研究[M].北京:地质出版社,2003.
[3]吴俊.突出煤的显微结构及表面特征研究[J].煤炭学报,1987,12(2):40-45.WU Jun.Study on micro-structure and surface fea-tures of coal prone to outburst[J].Journl of ChinaCoal Society,1987,12(2):40-45.
[4]张慧,王晓刚,员争荣,等.煤中显微裂隙的成因类型及其研究意义[J].岩石矿物学杂志,2002,21(3):278-284.ZHANG Hui,WANG Xiao-gang,YUAN Zheng-rong,et al.Genetic types of microfractures in coaland their significance[J].Acta Petrologica Et Miner-alogica,2002,21(3):278-284.
[5]聂继红,孙进步.瓦斯突出煤的显微结构研究[J].东北煤炭技术,1996(6):40-42.NIE Ji-hong,SUN Jin-bu.Study about microstruc-ture of gas-outburst coal[J].Coal Technology ofNortheast China,1996(6):40-42.
[6]张红日,王传云.突出煤的微观特征[J].煤田地质与勘探,2000,28(4):31-33.ZHANG Hong-ri,WANG Chuang-yun.Microscopiccharacteristics of burst coal seams[J].Coal geology&exploration,2000,28(4):31-33.
[7]刘文岗,姜耀东,周宏伟,等.冲击倾向性煤体的细观特征与裂纹失稳的试验研究[J].湖南科技大学学报,2006,21(4):14-18.LIU Wen-gang,JIANG Yao-dong,ZHOU Hong-wei,et al.Experimental study on outburst pronenesscoal seam of meso character and crack destabilization[J].Journal of Hunan University of Science&Tech-nology,2006,21(4):14-18.
[8]何学秋,王恩元,聂百胜,等.煤岩流变电磁动力学[M].北京:科学出版社,2003.
[9]李贺,尹光志,许江,等.岩石断裂力学[M].重庆:重庆大学出版社,1988.
[10][英]B R.劳恩,T R威尔肖.脆性断裂力学[M].陈颙,尹祥础,译.北京:地震出版社,1985.
[11]BRACE W F,PAULDING B W,SCHOLZ C.Di-latancy in the fracture of crystalline rock[J].J Geo-phys Res,1966,71:3936-3953.
[12]夏继祥,王岫霏.单轴压力下砂岩破裂过程的实验研究[J].西南交通大学学报,1982(4):40-47.XIA Jix-iang,WANG Xiu-fei.Experimental studyof the fracturing process of sandstone in uniaxialcompression[J].Journal of Southwest Jiaotong Uni-versity,1982(4):40-47.
[13]许江,李贺,尹光志,等.对单轴应力状态下砂岩微观断裂发展全过程的实验研究[J].力学与实践,1986(4):16-20.XU Jiang,LI He,YIN Guang-zhi,et al.Experi-mental study on the microscopic fracturing processof sandstone in uniaxial compression[J].Mechanicsand Engineering,1986(4):16-20.
[2]张慧,李小彦,赫琦,等.中国煤的扫描电子显微镜研究[M].北京:地质出版社,2003.
[3]吴俊.突出煤的显微结构及表面特征研究[J].煤炭学报,1987,12(2):40-45.WU Jun.Study on micro-structure and surface fea-tures of coal prone to outburst[J].Journl of ChinaCoal Society,1987,12(2):40-45.
[4]张慧,王晓刚,员争荣,等.煤中显微裂隙的成因类型及其研究意义[J].岩石矿物学杂志,2002,21(3):278-284.ZHANG Hui,WANG Xiao-gang,YUAN Zheng-rong,et al.Genetic types of microfractures in coaland their significance[J].Acta Petrologica Et Miner-alogica,2002,21(3):278-284.
[5]聂继红,孙进步.瓦斯突出煤的显微结构研究[J].东北煤炭技术,1996(6):40-42.NIE Ji-hong,SUN Jin-bu.Study about microstruc-ture of gas-outburst coal[J].Coal Technology ofNortheast China,1996(6):40-42.
[6]张红日,王传云.突出煤的微观特征[J].煤田地质与勘探,2000,28(4):31-33.ZHANG Hong-ri,WANG Chuang-yun.Microscopiccharacteristics of burst coal seams[J].Coal geology&exploration,2000,28(4):31-33.
[7]刘文岗,姜耀东,周宏伟,等.冲击倾向性煤体的细观特征与裂纹失稳的试验研究[J].湖南科技大学学报,2006,21(4):14-18.LIU Wen-gang,JIANG Yao-dong,ZHOU Hong-wei,et al.Experimental study on outburst pronenesscoal seam of meso character and crack destabilization[J].Journal of Hunan University of Science&Tech-nology,2006,21(4):14-18.
[8]何学秋,王恩元,聂百胜,等.煤岩流变电磁动力学[M].北京:科学出版社,2003.
[9]李贺,尹光志,许江,等.岩石断裂力学[M].重庆:重庆大学出版社,1988.
[10][英]B R.劳恩,T R威尔肖.脆性断裂力学[M].陈颙,尹祥础,译.北京:地震出版社,1985.
[11]BRACE W F,PAULDING B W,SCHOLZ C.Di-latancy in the fracture of crystalline rock[J].J Geo-phys Res,1966,71:3936-3953.
[12]夏继祥,王岫霏.单轴压力下砂岩破裂过程的实验研究[J].西南交通大学学报,1982(4):40-47.XIA Jix-iang,WANG Xiu-fei.Experimental studyof the fracturing process of sandstone in uniaxialcompression[J].Journal of Southwest Jiaotong Uni-versity,1982(4):40-47.
[13]许江,李贺,尹光志,等.对单轴应力状态下砂岩微观断裂发展全过程的实验研究[J].力学与实践,1986(4):16-20.XU Jiang,LI He,YIN Guang-zhi,et al.Experi-mental study on the microscopic fracturing processof sandstone in uniaxial compression[J].Mechanicsand Engineering,1986(4):16-20.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心