岩石劈裂与岩石破坏性质的不稳定性
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摘要
岩石劈裂是裂纹受轴向主压缩荷载引起的裂纹尖端开裂所致,这种开裂与Griffith理论的分析结果不同,它是一种与岩石压缩剪切破坏不同的压缩张拉破坏。基于Griffith裂纹分析方法,证明了裂纹尖端存在小拉应力极值,结合岩石破坏的渐进性特点,说明岩石在压缩过程中可以形成张拉破坏(劈裂破坏),这一破坏形式是修正的Griffith强度理论以外的另一种破坏形式。给出了岩石劈裂破坏的条件,即裂纹纵向荷载高且侧压力很小或为0,且没有后续荷载的进一步作用或荷载时间短,并通过岩石厚壁圆筒卸荷试验验证了该岩石劈裂破坏条件的合理性。基于能量原理,分析岩石卸荷在无外功条件下张拉破坏与压缩破坏的能量耗散特征,给出岩石破坏时的能量关系式;从能量的积聚与耗散角度,揭示了煤岩体动力冲击、巷道围岩突然破坏等动力破坏现象产生的机制。
Rock splits due to the axial main compression load at the crack tip. This splitting is a compression tension failure,which is different from the compression shear failure of the Griffith theory. At the crack tip,there exists the extreme value of the minor tension stress. Tensile failure or splitting failure appear during the compression process corresponding to the gradual characteristics of rock failure. This kind of failure is beyond the modified Griffith theory. The criterion of the occurrence of rock splitting is that the value of longitudinal load should be high and the value of lateral stress should be low or zero and that there is no subsequent loads or the loads last short. The criterion was confirmed with the unloading test of thick-wall cylinder rock. Based on the energy principle,the energy dissipation characteristics of tension failure and compression failure was analyzed under no external work condition during the unload process,and the energy relations of rock failure were obtained. From the energy accumulation and dissipation,the mechanisms of coal-rock dynamic impacting and sudden damage of surrounding rock were revealed.
Rock splits due to the axial main compression load at the crack tip. This splitting is a compression tension failure,which is different from the compression shear failure of the Griffith theory. At the crack tip,there exists the extreme value of the minor tension stress. Tensile failure or splitting failure appear during the compression process corresponding to the gradual characteristics of rock failure. This kind of failure is beyond the modified Griffith theory. The criterion of the occurrence of rock splitting is that the value of longitudinal load should be high and the value of lateral stress should be low or zero and that there is no subsequent loads or the loads last short. The criterion was confirmed with the unloading test of thick-wall cylinder rock. Based on the energy principle,the energy dissipation characteristics of tension failure and compression failure was analyzed under no external work condition during the unload process,and the energy relations of rock failure were obtained. From the energy accumulation and dissipation,the mechanisms of coal-rock dynamic impacting and sudden damage of surrounding rock were revealed.
引文
[1]GURNEY C,ROWE P W.Fracture of glass rods in bending and under radial pressure[R].[S.l.]:Aero Research Council,Reports and Memoranda,1945:2 284.
[2]BRIDGMAN P W.Reflections on rupture[J].Journal of Applied Physics,1938,9(8):517–528.
[3]GURNEY C,ROWE P W.The effect of radial pressure on the flow and fracture of reinforced plastic rods[R].[S.l.]:Aero Research Council,Reports and Memoranda,1945:2 284.
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[17]张黎明,王在泉,贺俊征,等.卸荷条件下岩爆机理的试验研究[J].岩石力学与工程学报,2005,24(增1):4 769–4 773.(ZHANG Liming,WANG Zaiquan,HE Junzheng,et al.Study on the experiment of rock burst under unloading condition[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(Supp.1):4 769–4 773.(in Chinese))
[18]张后全.厚壁圆筒高压卸载环状劈裂及相关力学行为研究[博士学位论文][D].徐州:中国矿业大学,2010.(ZHANG Houquan.Study of ringlike splitting failure of rock cylinders under unloading condition after high compression and its related mechanical behavior[Ph.D.Thesis][D].Xuzhou:China University of Mining and Technology,2010.(in Chinese))
[19]SANTARELLI F J,BROWN E T.Failure of three sedimentary rocks in triaxial and hollow cylinder compression tests[J].International Journal of Rock Mechanics and Mining Science and Geomechanics Abstracts,1989,26(5):401–413.
[20]刘志成.脆性岩石三轴卸荷实验研究[J].华北科技学院学报,2009,6(3):10–12.(LIU Zhicheng.Research on mechanics properties of the brittle rock with triaxial unloading experiment[J].Journal of North China Institute of Science and Technology,2009,6(3):10–12.(in Chinese))
[21]沈军辉,王兰生,王青海,等.卸荷岩体的变形破裂特征[J].岩石力学与工程学报,2003,22(12):2 028–2 031.(SHEN Junhui,WANG Langsheng,WANG Qinghai,et al.Deformation and fracture features of unloaded rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(12):2 028–2 031.(in Chinese))
[22]章梦涛,潘一山,刘成丹.矿井煤岩体变形失稳问题的研究[J].阜新矿业学院学报:自然科学版,1992,11(2):13–19.(ZHANG Mengtao,PAN Yishan,LIU Chengdan.The study of the instability problems of coal-rock mass in coal mine[J].Journal of Fuxin Mining Institute:Natural Science,1992,11(2):13–19.(in Chinese))
[23]ПЕТУХОВИМ,ЛИНЬКОВАМ.Механикагорныхударовивыбросов[M].Москова,Недра:[s.n.],1983:45–60.
[24]陆家佑.岩爆预测与防治中几个问题的研究现状[J].水电站设计,1993,(1):55–59.(LU Jiayou.Current study situation of rock burst prediction and prevention[J].Design of Hydroelectric Power Station,1993,(1):55–59.(in Chinese))
[25]贺永年,韩立军,王衍森.岩石力学简明教程[M].徐州:中国矿业大学出版社,2010:44–50.(HE Yongnian,HAN Lijun,WANG Yansen.Rock mechanics-a concise tutorial[M].Xuzhou:China University of Mining and Technology Press,2010:44–50.(in Chinese))
[26]贺永年.关于Griffith准则的Murrell三维推广[J].力学与实践,1990,12(5):22–24.(HE Yongnian.About the expand 3D Griffith′s strength theory by Muller[J].Mechanics and Its Practice,1990,12(5):22–24.(in Chinese))
[2]BRIDGMAN P W.Reflections on rupture[J].Journal of Applied Physics,1938,9(8):517–528.
[3]GURNEY C,ROWE P W.The effect of radial pressure on the flow and fracture of reinforced plastic rods[R].[S.l.]:Aero Research Council,Reports and Memoranda,1945:2 284.
[4]BRACE W F.Brittle fracture of rock[M].New York:Elsevier,1964:111–174.
[5]PUCHKOV L V,BAZHENOVE S L.Effect of longitudinal splitting on tensile strength of unidirectional aramid fiber reinforced plastics[J].Journal of Composite Materials,1992,26(10):1 402–1 426.
[6]NIE J G,WANG H G.Experimental study on splitting strength of composite steel-concrete beams[J].Journal of Building Structures,1997,18(2):13–19.
[7]HOLZHAUSEN G R,JOHNSON A M.Analyses of longitudinal splitting of uniaxially compressed rock cylinders[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1979,16(3):163–177.
[8]JAEGER J C,COOK N G W.Fundamentals of rock mechanics[M].3rd ed.London:Chapman and hall,1979:350–358.
[9]ADAMS G R,JAGER A J.Petroscopic observations of rock fracturing ahead of stope faces in deep-level gold mines[J].Journal of the South African Institute of Mining and Metallurgy,1980,80(6):204–209.
[10]ШЕМЯКИНЕИ,ФИСЕНКОГЛ,КУРЛЕЕНЯМВ,идр.Зональнаядезинтеграциягорныхпородвокрукподземныхвыработок,(ч4)[J].ФТПРПИ,2000,(4):3–26.
[11]HOEK E,BIENIAWSKI Z T.Brittle failure propagation in rock under compression[J].International Journal of Fracture Mechanics,1984,26(3):276–294.
[12]BRACE W F,BOMBOLAKIS E G.A note on brittle crack growth in compression[J].Journal of Geophysical Research,1963,68(12):3 709–3 713.
[13]PAUL B,GANGAL M.Initial and subsequent fracture curves for biaxial compression of brittle materials[C]//Proc.8th Symp.on Rock Mech.Minnesota:[s.n.],1966:1 000–1 005.
[14]MCLINTOCK F A,WALSH J B.Friction on Griffith cracks in rocks under pressure[C]//Proc.4th U.S.Nat.Congr.Appl.Mech.New York:Am.Soc.Mech.Eng.,1962:1 015–1 021.
[15]INGLIS C E.Stresses in a plate due to the presence of cracks and sharp corners[J].Trans.Inst.Naval Archit,1913,55:219–241.
[16]尤明庆,华安增.岩石试样的三轴卸围压试验[J].岩石力学与工程学报,1998,17(1):24–29.(YOU Mingqing,HUA Anzeng.Test of triaxial pressure reduction of rock specimens[J].Chinese Journal of Rock Mechanics and Engineering,1998,17(1):24–29.(in Chinese))
[17]张黎明,王在泉,贺俊征,等.卸荷条件下岩爆机理的试验研究[J].岩石力学与工程学报,2005,24(增1):4 769–4 773.(ZHANG Liming,WANG Zaiquan,HE Junzheng,et al.Study on the experiment of rock burst under unloading condition[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(Supp.1):4 769–4 773.(in Chinese))
[18]张后全.厚壁圆筒高压卸载环状劈裂及相关力学行为研究[博士学位论文][D].徐州:中国矿业大学,2010.(ZHANG Houquan.Study of ringlike splitting failure of rock cylinders under unloading condition after high compression and its related mechanical behavior[Ph.D.Thesis][D].Xuzhou:China University of Mining and Technology,2010.(in Chinese))
[19]SANTARELLI F J,BROWN E T.Failure of three sedimentary rocks in triaxial and hollow cylinder compression tests[J].International Journal of Rock Mechanics and Mining Science and Geomechanics Abstracts,1989,26(5):401–413.
[20]刘志成.脆性岩石三轴卸荷实验研究[J].华北科技学院学报,2009,6(3):10–12.(LIU Zhicheng.Research on mechanics properties of the brittle rock with triaxial unloading experiment[J].Journal of North China Institute of Science and Technology,2009,6(3):10–12.(in Chinese))
[21]沈军辉,王兰生,王青海,等.卸荷岩体的变形破裂特征[J].岩石力学与工程学报,2003,22(12):2 028–2 031.(SHEN Junhui,WANG Langsheng,WANG Qinghai,et al.Deformation and fracture features of unloaded rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(12):2 028–2 031.(in Chinese))
[22]章梦涛,潘一山,刘成丹.矿井煤岩体变形失稳问题的研究[J].阜新矿业学院学报:自然科学版,1992,11(2):13–19.(ZHANG Mengtao,PAN Yishan,LIU Chengdan.The study of the instability problems of coal-rock mass in coal mine[J].Journal of Fuxin Mining Institute:Natural Science,1992,11(2):13–19.(in Chinese))
[23]ПЕТУХОВИМ,ЛИНЬКОВАМ.Механикагорныхударовивыбросов[M].Москова,Недра:[s.n.],1983:45–60.
[24]陆家佑.岩爆预测与防治中几个问题的研究现状[J].水电站设计,1993,(1):55–59.(LU Jiayou.Current study situation of rock burst prediction and prevention[J].Design of Hydroelectric Power Station,1993,(1):55–59.(in Chinese))
[25]贺永年,韩立军,王衍森.岩石力学简明教程[M].徐州:中国矿业大学出版社,2010:44–50.(HE Yongnian,HAN Lijun,WANG Yansen.Rock mechanics-a concise tutorial[M].Xuzhou:China University of Mining and Technology Press,2010:44–50.(in Chinese))
[26]贺永年.关于Griffith准则的Murrell三维推广[J].力学与实践,1990,12(5):22–24.(HE Yongnian.About the expand 3D Griffith′s strength theory by Muller[J].Mechanics and Its Practice,1990,12(5):22–24.(in Chinese))