基于ANSYS接触单元模型的鲜水河断裂带库仑应力演化数值模拟
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摘要
鲜水河是青藏高原东缘一条活动性很强的左旋走滑断裂带.本文基于ANSYS接触单元模块平台,定量研究断裂带上1893年以来M 6.7级以上地震的相互作用,计算和分析了每次地震发生后,在周围其他断裂上产生的同震库伦应力改变对其后续地震的触发的影响.结果表明:鲜水河断裂带后续地震大多发生在前面强震引起的鲜水河破裂同震库伦应力增加的断裂段上,这说明强震对后续地震有相当的影响.最后通过将7次地震产生的库伦应力进行叠加,发现鲜水河断裂带有4处处于库伦应力增加区:(1)鲜水河断裂带的北部,即侏倭北部;(2)康定以南与龙门山断裂的交汇处;(3)道孚到乾宁段;(4)乾宁与康定中间地段.这4出库伦应力增加区与近20年鲜水河断裂带上M 3.0以上的地震分布吻合的很好,这说明了对鲜水河断裂带上强震的库伦应力状态研究,可为进一步揭示地震发生规律及圈定地震危险区提供线索.
Xianshuihe fault,located at the eastern Tibet Plateau,is a major active sinistral strike-slip fault in China.In this paper,based on the ANSYS software,we apply the method of contact element method to calculate the coulomb stress distribution of earthquakes with M≥6.7 along the fault zone since 1893,and then we discuss the interaction among those earthquakes.Commencing from analyzing the coulomb stress distribution of each earthquake, we discuss the relationship between the coulomb stress changes caused by previous earthquake and the mechanism of earthquake triggering.It is shown that each earthquake of the sequence occurred on the fault segment with coseimic coulomb stress increases caused by its predecessors,which vigorously prove that the influences of larger earthquakes do greatly affect the triggering of subsequent earthquakes.Finally,from the picture of superimposed stress of the seven strong earthquakes,we find that the coulomb stress increased areas concentrate at:(1)northern of Xianshuihe Fault;(2)the intersection of Kangding south part and Longmenshan fault belt;(3)Daofu-qianning fault;(4) Qianning-Kangding fault.Comparing with the earthquake distribution happened nearly 20 years on the Xianshuihe fault, we find that the earthquake activity concentrated on those 4 Coulomb increased zone,which might inform us that the study of coulomb stress changes along the Xianshuihe Fault can provide clues to find the law of earthquake origin and help to determine the earthquake risk area.
引文
Goodman R E,Taylor R L,Brekke T L.1968.A model for themechanics of jointed rock[J].Journal of the Soil Mechanics andFoundations Division,94(3):637-660.
    Heidbach O,Ben-Avraham Z.2007.Stress evolution and seismichazard of the Dead Sea Fault System[J].Earth and PlanetaryScience Letters,257(1-2):299-312.
    Harris R A.1998.Introduction to special section:Stress triggers,stress shadows,and implications for seismic hazard[J].Journalof Geophysical Research:Solid Earth,103(B10):24347-24358.
    King G C P,Stein R S,Lin J.1994.Static stress changes and thetriggering of earthquakes[J].Bul1.Seismological Society ofAmerica,84(3):935-953.
    Melosh H J,Williams C A Jr.1989.Mechanics of graben formationin crustal rocks:A finite element analysis[J].Journal ofGeophysical Research:Solid Earth,94(10):13961-13973.
    Okada Y.1992.Internal deformation due to shear and tensile faultsin a half-space[J].Bulletin of the Seismological Society ofAmerica,82(2):1018-1040.
    Parsons T,Stein R S,Simpson R W,et al.1999.Stress sensitivityof fault seismicity:a comparison between limited-offset obliqueand major strike-slip faults[J].Journal of geophysical research,104(B9):20183-20202.
    Papadimitriou E,Wen X Z,Karakostas V,et al.2004.Earthquaketriggering along the Xianshuihe fault zone of western Sichuan,China[J].Pure and Applied Geophysics,161(8):1683-1707.
    Shen Z K,LüJ N,Wang M,et al.2005.Contemporary crustaldeformation around the southeast borderland of the TibetanPlateau[J].Journal of Geophysical Research:Solid Earth,110(B11),doi:10.1029/2004JB003421.
    Wen X Z,Ma S L,Xu X L,et al.2008.Historical pattern andbehavior of earthquake ruptures along the eastern boundary ofthe Sichuan-Yunnan faulted-block,southwestern China[J].Physics of the Earth and Planetary Interiors,168(1-2):16-36.
    Xiong X,Shan B,Zheng Y,et al.2010.Stress transfer and itsimplication for earthquake hazard on the Kunlun Fault,Tibet[J].Tectonophysics,482(1-4):216-225.
    Ziv A,Rubin A M.2000.Static stress transfer and earthquaketriggering:No lower threshold in sight[J].Journal ofGeophysical Research:Solid Earth,105(B6):13631-13642.
    白武明,滕春凯,王新华.1990.鲜水河断裂带多断层相互作用的流变断裂力学分析[J].地球物理学报,33(3):308-318.
    杜方,闻学泽,张培震.2010.鲜水河断裂带炉霍段的震后滑动与形变[J].地球物理学报,53(10):2355-2366,doi:10.3969/j.issn.00015733.2010.10.009.
    邓起东.2002.中国活动构造研究的进展与展望[J].地质论评,48(2):168-177.
    邓起东,张培震,冉勇康,等.2002.中国活动构造基本特征[J].中国科学(D辑),32(12):1020-1030.
    李天袑,杜其方.1989.鲜水河断裂带炉霍段的水平运动及地震的重复性研究[J].地震地质,11(4):31-42.
    刘冠中,马瑾,张鸿旭,等.2013.二十年来蠕变和短基线观测反映的鲜水河断裂带活动特征[J].地球物理学报,56(3):878-891.
    冉洪流,何宏林.2006.鲜水河断裂带北西段不同破裂源强震震级(M≥617)及复发间隔研究[J].地球物理学报,49(1):153-161.
    闻学泽.2000.四川西部鲜水河-安宁河-则木河断裂带的地震破裂分段特征[J].地震地质,22(3):239-249.
    王辉,刘杰,石耀霖,等.2008.鲜水河断裂带强震相互作用的动力学模拟研究[J].中国科学:D辑,38(7):808-818.
    万永革,吴忠良,周公威,等.2002.地震应力触发研究[J].地震学报,24(5):533-551.
    韩渭宾,蒋国芳.2005.川滇地区较长时间尺度的地震活动盛衰交替性[J].地震,25(1):51-57.
    徐晶,邵志刚,马宏生,等.2013.鲜水河断裂带库仑应力演化与强震间关系[J].地球物理学报,56(4):1146-1158.
    石耀霖,曹建玲.2010.库仑应力计算及应用过程中若干问题的讨论-以汶川地震为例[J].地球物理学报,53(1):102-110.
    蜀水.1974.炉霍7.9级地震特征和该地区的地震活动性[J].地球物理学报,17(2):77-85.
    杨永林,苏琴.2007.鲜水河断裂带现今活动特征研究[J].大地测量与地球动力学,27(6):22-27.
    张周术,黄忠贤,王建军.1991.鲜水河断裂带强震活动的模拟[J].中国地震,7(3):72-79.
    张国民,尹京苑.2003.地震预报研究的发展展望[J].防震减灾工程学报,23(4):83-90.
    张秋文,张培震,王乘,等.2003.鲜水河断裂带断层间相互作用的触震与缓震效应[J].地震学报,25(2):143-153.
    曾海容,宋惠珍.1999.断裂端部特殊单元模型[J].地震地质,21(3):215-220.

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