大尺度断层活动性数值模拟及地震学类比
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摘要
本文建立了大尺度断层(100-1000 km)的二维模型,利用ANSYS有限元软件平台,采用接触模式,模拟了百年时间尺度走滑断层的位错运动.结果表明,不同的断层力学参数,特别在断层强度非均匀分布的状态下,断层位错运动存在明显的非均匀时、空分布的特征.然而,不同模型的断层位错运动还显示出一些共同的特征,即断层位错运动表现为闭锁期、准静态预滑期和瞬间滑动,以及与之相应的应力(应变)的积累、调整和释放等等.这些结果也与实验室内小尺度的岩石物理实验相类似.与此同时,模拟结果与实际地震活动表现出的重复性和准周期特征较为相似.模拟发现,对于参数分布较为复杂的断层模型,其数值模拟提示的地震过程相对复杂得多.对于一个近尺度近1000 km,在接触面上设置了两个剪切强度相对较大区域的断层模型而言,模拟对应地震活动显示,其模拟地震断层位错分段发生,其高强度的区域基本控制了断层的地震位错运动.整个断层的模拟地震位错呈现出了地震触发、震中迁移、大震重复等与实际地震活动性相似的特征.
Using contact algorithm in tinite element method (FEM), we have established 2D large scale faults models and simulated the dislocation of strike-slip faults in hundreds of years. The results show that the dislocations were nonlinear in space and time, especially in non-homogenous distribution of mechanical parameters on the fault surface. But different models show the same characters such as stick period, pre-slip period and instantly slip period. These results were resembled with experiments in laboratory. Additionally the simulation results were resembled with natural earthquakes in repetition and quasi-periodicity. In the model of 1000 km long fault, which we set two strong fault regions with high friction coefficient, the simulation results indicates, the simulated earthquakes were occurred in separate parts, and the strong fault regions control all fault's activity. We can also find the trigger of earthquake, transfers of the simulated earthquakes and the repetitions of large earthquakes in this model. The characteristics of large scale fault activity are comparable with the natural faults.
Using contact algorithm in tinite element method (FEM), we have established 2D large scale faults models and simulated the dislocation of strike-slip faults in hundreds of years. The results show that the dislocations were nonlinear in space and time, especially in non-homogenous distribution of mechanical parameters on the fault surface. But different models show the same characters such as stick period, pre-slip period and instantly slip period. These results were resembled with experiments in laboratory. Additionally the simulation results were resembled with natural earthquakes in repetition and quasi-periodicity. In the model of 1000 km long fault, which we set two strong fault regions with high friction coefficient, the simulation results indicates, the simulated earthquakes were occurred in separate parts, and the strong fault regions control all fault's activity. We can also find the trigger of earthquake, transfers of the simulated earthquakes and the repetitions of large earthquakes in this model. The characteristics of large scale fault activity are comparable with the natural faults.
引文
[1] 陈顒.地壳岩石的力学性能[M].北京:地震出版社,1988． Chen Y. The mechanical properties of rock in crust[M]. Beijing: Earthquake publishing house, 1988．
[2] Ohnaka M. Kuwahara Y, Yamamolo K, et al. Dynamic breakdown processes and the generating mechanism for high-frequency elastic radiation during stick-slip instabilities [J].Geophys Monogr,1986, 6 :13-24．
[3] 马胜利,刘力强,马瑾,等.均匀和非均匀断层滑动失稳成核过程的实验研究[J].中国科学(D),2003,33:45-52． Ma S L, Liu L Q, Ma Jin, et al. The laboratary study of the nucleation in homogeneous and heterogeneous slip-fault [J]. Science In China, 2003,33:45-52．
[4] 马瑾,刘力强,马胜利.断层几何与前兆偏离[J].中国地震,1999,15(2) ,106-115． Ma J, Liu L Q, Ma S L. Fault geometry and departure of precursors from epicenter[J]. Earthquake Reserch In China, 1999 ,15(2) : 106-115．
[5] Naoyuki Kato, Lei X L, Wen X Z. A synthetic seismicity model for the Xianshuihe fault, southwestern China: simulation using a rate-and state-dependent friction law[J].Geophys. J. Int, 2007,169:286-300．
[6] 郑洪伟,李廷栋,高锐,等.数值模拟在地球动力学中的研究进展[J].地球物理学进展,2006,21(2) :360-369 Zheng H W, Li T D, Gao R, et al. The advance of numerical dimulation in geodynamics[J]. Progress in Geophysics, 2006, 21(2) :360-369．
[7] Ruth A. Harris. Numerical simulations of large earthquakes: dynamic rupture propagation on heterogeneous faults[J]. Pure appl. Geophys,2004,161:2171-2181．
[8] 王凯英,马瑾.川滇地区断层相互作用的地震活动证据及有限元模拟[J].地震地质,2004,26(2) ,259-271． Wang K Y, Ma J. Seismic evidence and numerical simulation for fault interactions in Sichuan-Yunnan region[J]. Seismology and Geology,2004,26(2) :259-271．
[9] Li Q S, Liu M. Initiation of the san jacinto fault and its interaction with the san andreas fault : insights from geodynamic modeling [J]. Pure and Applied Geophysics,2007,164:1937-194．
[10] Burridge R, Knopoff L. Model and theoretical seismicity[J]. Bull Seismol Soc Am, 1967,57(3) :341-371．
[11] 于泳,洪汉净,等.粘弹性有限元与弹簧滑块耦合模型-断层地块相互作用的数值模拟[J].中国科学(D辑),2003,33(增刊):80-90． Yu Y, Hong H J, et al. The viscoelastic FEM BK model-the simulation of interaction of faults[J]. Science in China (D), 2003,33:80-90．
[12] Cao T, Aki K. Seismicity simulation with rale-and state- dependent friction law[J]. Pure Appl Geophys, 1986,124:487-513．
[13] Dieterich J H. A model for the nucleation of earthquake slip in Das S, Boatwrighl J , Scholz C H, eds. Earthquake source Mechanics [J]. Am Geophys Union, M. Ewing Vol 6． Geophys Mongor,37,1986． 37-47．
[14] Rice J R, Gu J-C. Earthquake after effects and triggered seismic phenomena[J]. Pure Appl Geophys, 1983,121:187-219．
[15] Barriere B, Turcotte D L. A scale-invariant cellular-automata model for distributed seismictiy [J]. Geophys Res Lett. , 1991,18(11) :2011-2014．
[16] 陆远忠,吕悦军.带断层的细胞自动机模型及算法复杂性[J].地震学报,1994,16(2) :183-189． Lu Y Z, Lii Y J. The model of cellular automata with faults and it's algorithm complexity[J]. Acta Seismologica Sinica, 1994,16(2) :183-189．
[17] 刘杰,刘桂萍,李丽.等.基于大陆地震活动特点建立的简化动力学模型--细胞自动机模型[J].地震,1999,19(3) :230-238． Liu Jie, Liu G P, Li L,et al. Simplified dynamic model based on the characteristic of continental seismicity-cell automat model[J]. Earthquake, 1999,19(3) :230-238．
[18] 刘桂萍,傅征祥,刘杰.摩擦时间依从的地震活动性细胞自动机模型[J].地球物理学报,2000,43(2) :203-212． Liu Guiping, Fu Z X, Liu J. A time-dependent friclonal cellular automation model of seismicity[J]. Chinese Journal of Geophysics,2000,43(2) :203-212．
[19] 朱守彪,蔡永恩,刘杰,等.利用三维细胞自动机模拟地震活动性[J].北京大学报,2006,(42) :206-210． Zhu S B, Cai Y E, Liu J, et al. Modeling seismicty by 3-D cellular automata, acta scientiarum naturalium universitatis pekinesis[J]. 2006,42(2) :206-210．
[20] 朱守彪,邢会林.谢富仁,等.地震发生过程的有限单元法模拟--以苏门答腊俯冲带上的大地震为例[J].地球物理学报,2008,51(2) :460-468． Zhu S B, Xing H L, Xie F R,et al. Simulation of earthquake processes by finite element method: the case of megathrust earthquakes on the Sumatra subduction zone[J]. Chinese Journal of Geophysics,2008,51(2) :460-468．
[21] Brace W F, Byerlee J D. Stick-slip as a Mechanism for Earthquakes[J]. Science, 1996,153:990-992．
[22] 郑文衡,陆明勇.地震动态触发机制的初步研究[J].地球物理学报,2005,48(1) :116-123． Zheng W H, Lu M Y. A preliminary study on mechanism of dynamic triggering of earthquakes [J]. Chinese Journal of Geophysics,2005,48(1) : 116-123．
[23] Oglesby D D. Earthquake dynamics on dip-slip faults [D].PhD thesis ,University of California, Santa Barbara, 1999．
[24] Burridge R. Admissible speeds for plane-strain self-similar shear cracks with friction but lacking cohesion[J]. Geophys. J. R. Astr. Soc. , 1973,35:439-455．
[25] 闻学泽,四川西部鲜水河-安宁河-则木河断裂带的地震破 裂分段特征[J].地震地质,2000,22(3) :239-249． Wen X Z. Character of rupture segmentation of the Xianshuihe-Anninghe-Zemuhe fault zone, western Sichuan [J]. Seismology and Geology,2000,22(3) :239-249．
[26] Byerlee J D. Static and kinetic friction of granite at high normal stress[J]. International Journal of Rock Mechanics and Mining Science. 1970, 7(6) : 577-582．
[27] 戴志阳,陈宇卫,傅容珊,等,前兆性地震平静研究[J].地球物理学进展,2006,21(1) :18-24． Dai Z Y, Chen Y W, Fu R S,et al. The study of precursory seismic quiescence[J]. Progress in Geophysics, 2006,21(1) : 18-24
[2] Ohnaka M. Kuwahara Y, Yamamolo K, et al. Dynamic breakdown processes and the generating mechanism for high-frequency elastic radiation during stick-slip instabilities [J].Geophys Monogr,1986, 6 :13-24．
[3] 马胜利,刘力强,马瑾,等.均匀和非均匀断层滑动失稳成核过程的实验研究[J].中国科学(D),2003,33:45-52． Ma S L, Liu L Q, Ma Jin, et al. The laboratary study of the nucleation in homogeneous and heterogeneous slip-fault [J]. Science In China, 2003,33:45-52．
[4] 马瑾,刘力强,马胜利.断层几何与前兆偏离[J].中国地震,1999,15(2) ,106-115． Ma J, Liu L Q, Ma S L. Fault geometry and departure of precursors from epicenter[J]. Earthquake Reserch In China, 1999 ,15(2) : 106-115．
[5] Naoyuki Kato, Lei X L, Wen X Z. A synthetic seismicity model for the Xianshuihe fault, southwestern China: simulation using a rate-and state-dependent friction law[J].Geophys. J. Int, 2007,169:286-300．
[6] 郑洪伟,李廷栋,高锐,等.数值模拟在地球动力学中的研究进展[J].地球物理学进展,2006,21(2) :360-369 Zheng H W, Li T D, Gao R, et al. The advance of numerical dimulation in geodynamics[J]. Progress in Geophysics, 2006, 21(2) :360-369．
[7] Ruth A. Harris. Numerical simulations of large earthquakes: dynamic rupture propagation on heterogeneous faults[J]. Pure appl. Geophys,2004,161:2171-2181．
[8] 王凯英,马瑾.川滇地区断层相互作用的地震活动证据及有限元模拟[J].地震地质,2004,26(2) ,259-271． Wang K Y, Ma J. Seismic evidence and numerical simulation for fault interactions in Sichuan-Yunnan region[J]. Seismology and Geology,2004,26(2) :259-271．
[9] Li Q S, Liu M. Initiation of the san jacinto fault and its interaction with the san andreas fault : insights from geodynamic modeling [J]. Pure and Applied Geophysics,2007,164:1937-194．
[10] Burridge R, Knopoff L. Model and theoretical seismicity[J]. Bull Seismol Soc Am, 1967,57(3) :341-371．
[11] 于泳,洪汉净,等.粘弹性有限元与弹簧滑块耦合模型-断层地块相互作用的数值模拟[J].中国科学(D辑),2003,33(增刊):80-90． Yu Y, Hong H J, et al. The viscoelastic FEM BK model-the simulation of interaction of faults[J]. Science in China (D), 2003,33:80-90．
[12] Cao T, Aki K. Seismicity simulation with rale-and state- dependent friction law[J]. Pure Appl Geophys, 1986,124:487-513．
[13] Dieterich J H. A model for the nucleation of earthquake slip in Das S, Boatwrighl J , Scholz C H, eds. Earthquake source Mechanics [J]. Am Geophys Union, M. Ewing Vol 6． Geophys Mongor,37,1986． 37-47．
[14] Rice J R, Gu J-C. Earthquake after effects and triggered seismic phenomena[J]. Pure Appl Geophys, 1983,121:187-219．
[15] Barriere B, Turcotte D L. A scale-invariant cellular-automata model for distributed seismictiy [J]. Geophys Res Lett. , 1991,18(11) :2011-2014．
[16] 陆远忠,吕悦军.带断层的细胞自动机模型及算法复杂性[J].地震学报,1994,16(2) :183-189． Lu Y Z, Lii Y J. The model of cellular automata with faults and it's algorithm complexity[J]. Acta Seismologica Sinica, 1994,16(2) :183-189．
[17] 刘杰,刘桂萍,李丽.等.基于大陆地震活动特点建立的简化动力学模型--细胞自动机模型[J].地震,1999,19(3) :230-238． Liu Jie, Liu G P, Li L,et al. Simplified dynamic model based on the characteristic of continental seismicity-cell automat model[J]. Earthquake, 1999,19(3) :230-238．
[18] 刘桂萍,傅征祥,刘杰.摩擦时间依从的地震活动性细胞自动机模型[J].地球物理学报,2000,43(2) :203-212． Liu Guiping, Fu Z X, Liu J. A time-dependent friclonal cellular automation model of seismicity[J]. Chinese Journal of Geophysics,2000,43(2) :203-212．
[19] 朱守彪,蔡永恩,刘杰,等.利用三维细胞自动机模拟地震活动性[J].北京大学报,2006,(42) :206-210． Zhu S B, Cai Y E, Liu J, et al. Modeling seismicty by 3-D cellular automata, acta scientiarum naturalium universitatis pekinesis[J]. 2006,42(2) :206-210．
[20] 朱守彪,邢会林.谢富仁,等.地震发生过程的有限单元法模拟--以苏门答腊俯冲带上的大地震为例[J].地球物理学报,2008,51(2) :460-468． Zhu S B, Xing H L, Xie F R,et al. Simulation of earthquake processes by finite element method: the case of megathrust earthquakes on the Sumatra subduction zone[J]. Chinese Journal of Geophysics,2008,51(2) :460-468．
[21] Brace W F, Byerlee J D. Stick-slip as a Mechanism for Earthquakes[J]. Science, 1996,153:990-992．
[22] 郑文衡,陆明勇.地震动态触发机制的初步研究[J].地球物理学报,2005,48(1) :116-123． Zheng W H, Lu M Y. A preliminary study on mechanism of dynamic triggering of earthquakes [J]. Chinese Journal of Geophysics,2005,48(1) : 116-123．
[23] Oglesby D D. Earthquake dynamics on dip-slip faults [D].PhD thesis ,University of California, Santa Barbara, 1999．
[24] Burridge R. Admissible speeds for plane-strain self-similar shear cracks with friction but lacking cohesion[J]. Geophys. J. R. Astr. Soc. , 1973,35:439-455．
[25] 闻学泽,四川西部鲜水河-安宁河-则木河断裂带的地震破 裂分段特征[J].地震地质,2000,22(3) :239-249． Wen X Z. Character of rupture segmentation of the Xianshuihe-Anninghe-Zemuhe fault zone, western Sichuan [J]. Seismology and Geology,2000,22(3) :239-249．
[26] Byerlee J D. Static and kinetic friction of granite at high normal stress[J]. International Journal of Rock Mechanics and Mining Science. 1970, 7(6) : 577-582．
[27] 戴志阳,陈宇卫,傅容珊,等,前兆性地震平静研究[J].地球物理学进展,2006,21(1) :18-24． Dai Z Y, Chen Y W, Fu R S,et al. The study of precursory seismic quiescence[J]. Progress in Geophysics, 2006,21(1) : 18-24
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