加载速度对断层-围岩系统变形及快速回跳的影响
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摘要
在平面应变状态下,采用拉格朗日元法模拟了加载速度对断层-围岩系统形成时的应力水平、塑性区尺寸及剪切带图案、系统的最大承载能力以及快速回跳发生时的应力水平的影响。在数值计算中,采用了莫尔-库仑与拉破坏复合的破坏准则。峰后岩石的本构关系为线性应变软化。通常断层带-围岩系统形成之后系统的承载能力达到最大,之后系统的承载能力开始下降处于应变软化状态。当位于试样加载端上的单元的压缩应力-压缩位移曲线的峰后刚度足够大时,系统就会发生弹性回跳现象,即失稳破坏。随着加载速度的增加,断层带-围岩系统形成时的应力水平、断层带-围岩系统的最大承载能力、快速回跳发生时的应力水平及上述三者所对应的加载端部位移都增加,屈服单元数目增多,塑性区域不再保持平直,这都将大大增加系统的变形阻力。当加载速度较大时,较高的剪切应变率集中在断层带位置及断层带之外的弹性体的某些区域都是可能的。
Influences of loading rate on the stress level when a system composed of fault band and elastic rock was formed,the size of plastic zones,the patterns of localized shear band,the maximum load-carrying capability of the system,and on the stress level when the snap-back of the system occurred were modeled numerically by FLAC(Fast Lagrangian Analysis of Continua).The adopted failure criterion was a composite Mohr-Coulomb criterion with tension cut-off;and a linear strain-softening post-peak constitutive relation of rock was adopted.In general,after fault band-elastic body system is generated,the load-carrying capability of the system reaches its maximum value.Thereafter,it begins to decrease so that the system is in strain-softening stage.If the post-peak stiffness of compressive stress-compressive displacement curve for the monitored element at loading end of plane strain specimen is high enough,the snap-back(unstable failure) of the system occurs.As loading rate increases,the stress level corresponding to the formation of the system and the corresponding displacement increase;the maximum load-carrying capability of the system and the corresponding displacement increase;the stress level when the snap-back of the system occurs and the corresponding displacement increase.As loading rate increases,the number of yielded elements increases and the thickness of fault band no loner remains a constant,leading to an increase in deformation resistant of the system.For higher loading rate,it is possible that higher shear strain rates are concentrated into both fault band and some elements remaining elastic outside the band.
Influences of loading rate on the stress level when a system composed of fault band and elastic rock was formed,the size of plastic zones,the patterns of localized shear band,the maximum load-carrying capability of the system,and on the stress level when the snap-back of the system occurred were modeled numerically by FLAC(Fast Lagrangian Analysis of Continua).The adopted failure criterion was a composite Mohr-Coulomb criterion with tension cut-off;and a linear strain-softening post-peak constitutive relation of rock was adopted.In general,after fault band-elastic body system is generated,the load-carrying capability of the system reaches its maximum value.Thereafter,it begins to decrease so that the system is in strain-softening stage.If the post-peak stiffness of compressive stress-compressive displacement curve for the monitored element at loading end of plane strain specimen is high enough,the snap-back(unstable failure) of the system occurs.As loading rate increases,the stress level corresponding to the formation of the system and the corresponding displacement increase;the maximum load-carrying capability of the system and the corresponding displacement increase;the stress level when the snap-back of the system occurs and the corresponding displacement increase.As loading rate increases,the number of yielded elements increases and the thickness of fault band no loner remains a constant,leading to an increase in deformation resistant of the system.For higher loading rate,it is possible that higher shear strain rates are concentrated into both fault band and some elements remaining elastic outside the band.
引文
[1]殷有泉,张宏.断裂带内介质的软化特性和地震的非稳定模型[J].地震学报,1984,6(2):135-145.YIN You-quan,ZHANG Hong.The softening behaviour of fault zone medium and an instability model of earthquakes[J].Acta Seismological Sinica,1984,6(2):135-145.
[2]潘一山,王来贵,章梦涛,等.断层冲击地压发生的理论与试验研究[J].岩石力学与工程学报,1998,17(6):642-649.PAN Yi-shan,WANG Lai-gui,ZHANG Meng-tao,et al.The theoretical and testing study of fault rockburst[J].Chinese Journal of Rock Mechanics and Engineering,1998,17(6):642-649.
[3]潘岳,刘英,顾善发.矿井断层冲击地压的折迭突变模型[J].岩石力学与工程学报,2001,20(1):43-48.PAN Yue,LIU Ying,GU Shan-fa.Fold catastrophe model of mining fault rockburst[J].Chinese Journal of Rock Mechanics and Engineering,2001,20(1):43-48.
[4]王学滨,潘一山,任伟杰.基于应变梯度理论的岩石试件剪切破坏失稳判据及应用[J].岩石力学与工程学报,2003,22(5):747-750.WANG Xue-bin,PAN Yi-shan,REN Wei-jie.Instability of shear failure and application for rock specimen based on gradient-dependent plasticity[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(5):747-750.
[5]王学滨,潘一山,马谨.剪切带-弹性岩体系统的稳定及失稳滑动理论研究[J].岩土工程学报,2002,24(3):360-363.WANG Xue-bin,PAN Yi-shan,MA Jin.Theoretical analysis of stability and unstable sliding of the system composed of shear band and elastic rock[J].Chinese Journal of Geotechnical Engineering,2002,24(3):360-363.
[6]王学滨,赵扬锋,张智慧,等.考虑应变率及应变梯度效应的断层岩爆分析[J].岩石力学与工程学报,2003,22(11):1 859-1 862.WANG Xue-bin,ZHAO Yang-feng,ZHANG Zhi-hui,et al.Analysis of fault rockburst considering strain rate and strain gradient[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(11):1 859-1 862.
[7]WANG Xue-bin,YANG Xiao-bin,ZHANG Zhi-hui,et al.Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion[J].Journal of University of Science and Technology Beijing,2004,11(1):5-9.
[8]WANG Xue-bin,DAI Shu-hong,HAI Long,et al.Quantitative calculation of dissipated energy of fault rock burst based on gradient-dependent plasticity[J].Journal of University of Science and Technology Beijing,2004,11(3):197-201.
[9]徐思朋,缪协兴.冲击地压的时间效应研究现状[J].矿业安全与环保,2001,28(2):27-29.XU Si-peng,MIAO Xie-xing.Progress of time effect of rock burst[J].Mining Safety&Environmental Protection,2001,28(2):27-29.
[10]窦林名,何学秋,Bernard Drzezls.冲击矿压危险性评价的地音法[J].中国矿业大学学报,2000,29(1):85-88.DOU Lin-ming,HE Xue-qiu,Bernard Drzezls.AE method of evaluating the danger of rock burst[J].Journal of China University of Mining&Technology,2000,29(1):85-88.
[11]WANG Xue-bin.Strain localization of rock failure and instability criterion of rockburst[A].Progress in Safety Science and Technology(Vol IV)[C].WANG Ya-jun et al.ed.Beijing:Science Press,2004.244-249.
[12]WANG Xue-bin.Numerical simulation of influence of shear dilatancy on deformation characteristics of shear band-elastic body system[J].Journal of Coal Science&Engineering(China),2004,10(2):1-6.
[13]TANG Chun-an,FU Yu-fang,ZHAO Wen.A new approach to numerical simulation of source development of earthquake[J].Acta Seismologica Sinica,1997,10(4):425-434.
[14]林鹏,唐春安,陈忠辉,等.二岩体系统破坏全过程的数值模拟和实验研究[J].地震,1999,19(4):413-418.LIN Peng,TANG Chun-an,CHEN Zhong-hui,et al.Numerical and experimental study of deformation and failure behavior in a double rock specimen system[J].Earthquake,1999,19(4):413-418.
[2]潘一山,王来贵,章梦涛,等.断层冲击地压发生的理论与试验研究[J].岩石力学与工程学报,1998,17(6):642-649.PAN Yi-shan,WANG Lai-gui,ZHANG Meng-tao,et al.The theoretical and testing study of fault rockburst[J].Chinese Journal of Rock Mechanics and Engineering,1998,17(6):642-649.
[3]潘岳,刘英,顾善发.矿井断层冲击地压的折迭突变模型[J].岩石力学与工程学报,2001,20(1):43-48.PAN Yue,LIU Ying,GU Shan-fa.Fold catastrophe model of mining fault rockburst[J].Chinese Journal of Rock Mechanics and Engineering,2001,20(1):43-48.
[4]王学滨,潘一山,任伟杰.基于应变梯度理论的岩石试件剪切破坏失稳判据及应用[J].岩石力学与工程学报,2003,22(5):747-750.WANG Xue-bin,PAN Yi-shan,REN Wei-jie.Instability of shear failure and application for rock specimen based on gradient-dependent plasticity[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(5):747-750.
[5]王学滨,潘一山,马谨.剪切带-弹性岩体系统的稳定及失稳滑动理论研究[J].岩土工程学报,2002,24(3):360-363.WANG Xue-bin,PAN Yi-shan,MA Jin.Theoretical analysis of stability and unstable sliding of the system composed of shear band and elastic rock[J].Chinese Journal of Geotechnical Engineering,2002,24(3):360-363.
[6]王学滨,赵扬锋,张智慧,等.考虑应变率及应变梯度效应的断层岩爆分析[J].岩石力学与工程学报,2003,22(11):1 859-1 862.WANG Xue-bin,ZHAO Yang-feng,ZHANG Zhi-hui,et al.Analysis of fault rockburst considering strain rate and strain gradient[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(11):1 859-1 862.
[7]WANG Xue-bin,YANG Xiao-bin,ZHANG Zhi-hui,et al.Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion[J].Journal of University of Science and Technology Beijing,2004,11(1):5-9.
[8]WANG Xue-bin,DAI Shu-hong,HAI Long,et al.Quantitative calculation of dissipated energy of fault rock burst based on gradient-dependent plasticity[J].Journal of University of Science and Technology Beijing,2004,11(3):197-201.
[9]徐思朋,缪协兴.冲击地压的时间效应研究现状[J].矿业安全与环保,2001,28(2):27-29.XU Si-peng,MIAO Xie-xing.Progress of time effect of rock burst[J].Mining Safety&Environmental Protection,2001,28(2):27-29.
[10]窦林名,何学秋,Bernard Drzezls.冲击矿压危险性评价的地音法[J].中国矿业大学学报,2000,29(1):85-88.DOU Lin-ming,HE Xue-qiu,Bernard Drzezls.AE method of evaluating the danger of rock burst[J].Journal of China University of Mining&Technology,2000,29(1):85-88.
[11]WANG Xue-bin.Strain localization of rock failure and instability criterion of rockburst[A].Progress in Safety Science and Technology(Vol IV)[C].WANG Ya-jun et al.ed.Beijing:Science Press,2004.244-249.
[12]WANG Xue-bin.Numerical simulation of influence of shear dilatancy on deformation characteristics of shear band-elastic body system[J].Journal of Coal Science&Engineering(China),2004,10(2):1-6.
[13]TANG Chun-an,FU Yu-fang,ZHAO Wen.A new approach to numerical simulation of source development of earthquake[J].Acta Seismologica Sinica,1997,10(4):425-434.
[14]林鹏,唐春安,陈忠辉,等.二岩体系统破坏全过程的数值模拟和实验研究[J].地震,1999,19(4):413-418.LIN Peng,TANG Chun-an,CHEN Zhong-hui,et al.Numerical and experimental study of deformation and failure behavior in a double rock specimen system[J].Earthquake,1999,19(4):413-418.
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