汶川5.12地震发震机理的数值模拟
|
摘要
将围岩看成弹性体,断层看成具有应变软化的弹塑性体,断层和围岩组成统一的地质介质系统。在给定的地应力、孔隙压力及边界位移的作用下,应力逐渐积累,当达到断层强度时,断层进入塑性状态,应变随之软化,应力突然下降,能量突然释放,形成地震。根据这个原理,利用有限差分FLAC软件,对汶川5.12地震的机理进行了模拟。模拟结果证实:汶川5.12地震是在青藏高原侧向挤压,四川盆地阻挡,使龙门山断裂带受到缓慢增加的挤压应力场作用下形成的。计算结果给出了应力降、能量释放量、断层错动量、地震同震位移、震前位移、地震复发周期等重要参数,结果与野外调查及其它资料给出的数据具有较好的一致性。
In this paper,strain softening model is used for modeling the Wenchuan earthquake.Results shows that this earthquake was caused by compressing of Qinghai-Tibet Plateau and block of Sichuan Basin.The stress drop,energy release amount,the magnitude of dislocation of fault,coseismic displacement,displacement before earthquake and earthquake recurrence intervals are given by the modeling.The modeling results are in good agreement with geologic and geomorphologic survey and others data.
In this paper,strain softening model is used for modeling the Wenchuan earthquake.Results shows that this earthquake was caused by compressing of Qinghai-Tibet Plateau and block of Sichuan Basin.The stress drop,energy release amount,the magnitude of dislocation of fault,coseismic displacement,displacement before earthquake and earthquake recurrence intervals are given by the modeling.The modeling results are in good agreement with geologic and geomorphologic survey and others data.
引文
[1]张永双,雷伟志,石菊松,等.四川5.12地震次生地质灾害的基本特征初析[J].地质力学学报,2008,14(2):109~116.ZHANG Yong-shuang,LEI Wei-zhi,SHI Ju-song,et al.General characteristics of 5.12 earthquake-induced geo-hazards inSichuan[J].Journal of Geomechanics,2008,14(2):109~116.
[2]张永双,石菊松,孙萍,等.汶川地震内外动力耦合及灾害实例[J].地质力学学报,2009,15(2):131~141.ZHANG Yong-shuang,SHI Ju-song,SUN Ping,et al.General manifestation of coupling processes between endogenic andexogenic geological processes in 5.12 Wenchuan earthquake[J].Journal of Geomechanics,2009,15(2):131~141.
[3]董树文,张岳桥,龙长兴,等.四川汶川MS810地震地表破裂构造初步调查与发震背景分析[J].地球学报,2008,29(3):392~396.DONG Shu-wen,ZHANG Yue-qiao,LONG Chang-xing,et al.Surface rupture investigation of the WenchuanMS8.0 earthquakeof May 12th,2008,west Sichuan,and analysis of its occurrence setting[J].Acta Geoscientica Sinica,2008,29(3):392~396.
[4]吴珍汉,张作辰.四川汶川MS8.0级地震的地表变形与同震位移[J].地质通报,2008,27(12):2067~2075.WU Zhen-han,ZHANG Zuo-chen.Seismic deformation and co-seismic displacement of theMS8.0 Wenchuan earthquake inSichuan,China[J].Geological Bulletin of China,2008,27(12):2067~2075.
[5]徐锡伟,闻学泽,叶建青,等.汶川MS8.0地震地表破裂带及其发展构造[J].地震地质,2008,30(3):597~629.XU Xi-wei,WEN Xue-ze,YE Jian-qing,et al.TheMS8.0 Wenchuan earthquake surface ruptures and its seismogenic structure[J].Seismology and Geology,2008,30(3):597~629.
[6]何宏林,孙昭民,魏占玉,等.2008汶川MS8.0地震地表破裂带白沙河段破裂及其位移特征[J].地震地质,30(3):658~673.HE Hong-lin,SUN Zhao-min,WEI Zhan-yu,et al.Rupture of theMS8.0 Wenchuan earthquake along Bashahe River[J].Seismology and Geology,2008,30(3):658~673.
[7]杜义,谢富仁,张效亮,等.汶川MS8.0级地震断层滑动机制研究[J].地球物理学报,2009,52(2):464~473.DU Yi,XIE Fu-ren,ZHANG Xiao-liang,et al.The mechanics of fault slip ofMS8.0 Wenchuan earthquake[J].ChineseJournal of Geophysics,2009,52(2):464~473.
[8]陈祖安,林邦慧,白武明,等.2008年汶川8.0级地震孕震机理研究[J].地球物理学报,2009,52(2):408~417.CHEN Zu-an,LIN Bang-hui,BAI Wu-ming,et al.The mechanism of generation of May 12,2008MS8.0 Wenchuanearthquake[J].Chinese Journal of Geophysics,2009,52(2):408~417.
[9]朱守彪,张培震.2008年汶川MS8.0地震发生过程的动力学机制研究[J].地球物理学报,2009,52(2):418~427.ZHU Shou-biao,ZHANG Pei-zhen.A study on the dynamical mechanisms of the WenchuanMS8.0 earthquake,2008[J].Chinese Journal of Geophysics,2009,52(2):418~427.
[10]彭华,马秀敏,姜景捷.山丹地应力监测站体应变仪的地震效应[J].地质力学学报,2008,14(2):97~108.PENG Hua,MA Xiu-min,JIANG Jing-jie.Analysis of the volume strain data from the Shandan in-situ stress Monitoring Station[J].Journal of Geomechanics,2008,14(2):97~108.
[11]彭华,马秀敏,姜景捷.龙门山北端青川断层附近应力测量与断层稳定性[J].地质力学学报,2009,15(2):114~130.PENG Hua,MA Xiumin,JIANG Jingjie.Stability and stress measurement near the Qingchuan fault in the northern LongmenMountains[J].Journal of Geomechanics,2009,15(2):114~130.
[12]王连捷,周春景,孙东生,等.汶川5.12地震引起的库仑应力变化及其对周边地震活动的影响[J].地质力学学报,2008,14(3):193~200.WANG Lian-jie,ZHOU Chun-jing,SUN Dong-sheng,et al.Coulomb stress changes caused by Wenchuan earthquake and itsinfluence on seismic activity in the adjacent area[J].Journal of Geomechanics,2008,14(3):193~200.
[13]谭成轩,孙叶,吴树仁,等.“5.12”汶川MS8.0大地震后关于我国区域地壳稳定性评价的思考[J].地质力学学报,2009,15(2):142~150.TAN Cheng-xuan,SUN Ye,WU Shu-ren,et al.A consideration on regional crustal stability assessment after 5.12 WenchuanMS8.0 strong earthquake in China[J].Journal of Geomechanics,2009,15(2):142~150.
[14]姚鑫,张永双.基于差分干涉雷达的汶川地震同震形变特点[J].地质力学学报,2009,15(2):151~161.YAO Xin,ZHANG Yong-shuang.Co-seismic deformation of 5.12 Wenchuan earthquake based on D-InSAR[J].Journal ofGeomechanics,2009,15(2):151~161.
[15]陈.地壳岩石的力学性能——理论基础与试验方法[M].北京:地震出版社,1988.CHEN Yu.Mechanical properties of crest rock:Theoretical foundation and experimental methods[M].Beijing:SeismologicalPress,1988.
[16]耶格J C,库克N G W.岩石力学基础[M].中国科学院工程力学研究所(译).北京:地震出版,1981.1~690.Jaeger J C,Cook N G W.Fundamentals of rock mechanics[M].Institute of Engineering Mechanics,Chinese Academy ofSciences(Translated).Beijing:Seismological Press,1981.1~690.
[17]Rice J R.Theory of precursory processes in the inception of earthquake rupture[J].Gerlands Beitrage zur Geophysik,1979,88:91~127.
[18]Stuart W D.Quasi-static earthquake mechanics[J].Reviews of Geophysics and Space Physics,1979,17(6):1115~1120.
[19]Goodman R E,Taylor R L,Brekke T L.A model for the mechanics of jointed rock[J].Journal of the Soil Mechanics andFoundations Division,1968,94(3):637~660.
[20]Zienkiewicz O C,Taylor R L.The finite element method(fifth edition)[M].Oxford:Butterworth-Heinemann,2000.
[21]殷有泉,张宏,模拟地震的应变软化的数学模型[J].地球物理学报,1982,25(5):414~423.YIN You-quan,ZHANG Hong.A mathematical model of strain softening in simulating earthquake[J].Acta Geophysica Sinica,1982,25(5):414~423.
[22]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].ActaSeismologica Sinica,1984,6(2):135~145.
[23]殷有泉.非线性有限元基础[M].北京:北京大学出版社,2007.YIN You-quan.Non-linear finite element method[M].Beijing:Peking University Press,2007.
[24]陈运泰,许力生,张勇,等.2008年5月12日汶川特大地震震源特性分析报告[R/OL].http://www.csi.ac.cn/sichuan/chenyuntai.pdf.CHEN Yun-tai,XU Li-sheng,ZHANG Yong,et al.Report of the great Wenchuan earthquake source of May 12,2008[R/OL].http://www.csi.ac.cn/sichuan/chenyuntai.pdf.
[25]安其美,丁立丰,王海忠,等.龙门山断裂带的性质与活动性研究[J].大地测量与地球动力学,2004,24(2):115~119.AN Qi-mei,DING Li-feng,WANG Hai-zhong,et al.Research of property and activity of Longmen Mountain fault zone[J].Journal of Geodesy and Geodynamics,2004,24(2):115~119.
[26]赖锡安,黄立文.中国大陆现今地壳运动[M].北京:地震出版社,2004.LAI Xi-an,HUANG Li-wen.Current crustal movement in Chinese mainland[M].Beijing:Seismological Press,2004.
[27]笠原庆一.地震力学[M].赵仲和(译).北京:地震出版社,1984.Kasahara K.Earthquake mechanics[M].ZHAO Zhong-he(translated).Beijing:Seismological Press,1984.
[28]李海兵,王宗秀,付小方,等.2008年5月12日汶川地震(MS8.0)地表破裂带的分布特征[J].中国地质,2008,35(5):803~813.LI Hai-bing,WANG Zong-xiu,FU Xiao-fang,et al.The surface rupture zone distribution of the Wenchuan earthquake(MS8.0)happened on May 12th,2008[J].Geology in China,2008,35(5):803~813.
[29]李勇,周荣军,Densmore A L,等.青藏高原东缘龙门山晚新生代走滑-逆冲作用的地貌标志[J].第四纪研究,2006,26(1):40~51.LI Yong,ZHOU Rong-jun,Densmore A L,et al.Geomorphic evidence for the Late Cenozoic strike-slipping and thrusting inLongmen Mountain at the eastern margin of the Tibetan Plateau[J].Quaternary Sciences,2006,26(1):40~51.
[30]张培震,徐锡伟,闻学泽,等.2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因[J].地球物理学报,2008,51(4):1066~1073.ZHANG Pei-zhen,XU Xi-wei,WEN Xue-ze,et al.Slip rates and recurrence intervals of the Longmen Shan active fault zone,and tectonic implications for the mechanism of the May 12 Wenchuan earthquake,2008,Sichuan,China[J].Chinese Journalof Geophysics,2008,51(4):1066~1073.
[31]Densmore A L,Ellis M A,LI Yong,et al.Active tectonics of the Beichuan and Pengguan faults at the eastern margin of theTibetan Plateau[J].Tectonics,2007,26,doi:10.1029/2006TC001987.
[32]Burchfiel B C,Royden L H,van der Hilst R D,et al.A geological and geophysical context for the Wenchuan earthquake of 12May,2008,Sichuan,People s Republic of China[J].GSA Today,2008,18(7):4~11.doi:10.1130/GSATG18A.1.
[2]张永双,石菊松,孙萍,等.汶川地震内外动力耦合及灾害实例[J].地质力学学报,2009,15(2):131~141.ZHANG Yong-shuang,SHI Ju-song,SUN Ping,et al.General manifestation of coupling processes between endogenic andexogenic geological processes in 5.12 Wenchuan earthquake[J].Journal of Geomechanics,2009,15(2):131~141.
[3]董树文,张岳桥,龙长兴,等.四川汶川MS810地震地表破裂构造初步调查与发震背景分析[J].地球学报,2008,29(3):392~396.DONG Shu-wen,ZHANG Yue-qiao,LONG Chang-xing,et al.Surface rupture investigation of the WenchuanMS8.0 earthquakeof May 12th,2008,west Sichuan,and analysis of its occurrence setting[J].Acta Geoscientica Sinica,2008,29(3):392~396.
[4]吴珍汉,张作辰.四川汶川MS8.0级地震的地表变形与同震位移[J].地质通报,2008,27(12):2067~2075.WU Zhen-han,ZHANG Zuo-chen.Seismic deformation and co-seismic displacement of theMS8.0 Wenchuan earthquake inSichuan,China[J].Geological Bulletin of China,2008,27(12):2067~2075.
[5]徐锡伟,闻学泽,叶建青,等.汶川MS8.0地震地表破裂带及其发展构造[J].地震地质,2008,30(3):597~629.XU Xi-wei,WEN Xue-ze,YE Jian-qing,et al.TheMS8.0 Wenchuan earthquake surface ruptures and its seismogenic structure[J].Seismology and Geology,2008,30(3):597~629.
[6]何宏林,孙昭民,魏占玉,等.2008汶川MS8.0地震地表破裂带白沙河段破裂及其位移特征[J].地震地质,30(3):658~673.HE Hong-lin,SUN Zhao-min,WEI Zhan-yu,et al.Rupture of theMS8.0 Wenchuan earthquake along Bashahe River[J].Seismology and Geology,2008,30(3):658~673.
[7]杜义,谢富仁,张效亮,等.汶川MS8.0级地震断层滑动机制研究[J].地球物理学报,2009,52(2):464~473.DU Yi,XIE Fu-ren,ZHANG Xiao-liang,et al.The mechanics of fault slip ofMS8.0 Wenchuan earthquake[J].ChineseJournal of Geophysics,2009,52(2):464~473.
[8]陈祖安,林邦慧,白武明,等.2008年汶川8.0级地震孕震机理研究[J].地球物理学报,2009,52(2):408~417.CHEN Zu-an,LIN Bang-hui,BAI Wu-ming,et al.The mechanism of generation of May 12,2008MS8.0 Wenchuanearthquake[J].Chinese Journal of Geophysics,2009,52(2):408~417.
[9]朱守彪,张培震.2008年汶川MS8.0地震发生过程的动力学机制研究[J].地球物理学报,2009,52(2):418~427.ZHU Shou-biao,ZHANG Pei-zhen.A study on the dynamical mechanisms of the WenchuanMS8.0 earthquake,2008[J].Chinese Journal of Geophysics,2009,52(2):418~427.
[10]彭华,马秀敏,姜景捷.山丹地应力监测站体应变仪的地震效应[J].地质力学学报,2008,14(2):97~108.PENG Hua,MA Xiu-min,JIANG Jing-jie.Analysis of the volume strain data from the Shandan in-situ stress Monitoring Station[J].Journal of Geomechanics,2008,14(2):97~108.
[11]彭华,马秀敏,姜景捷.龙门山北端青川断层附近应力测量与断层稳定性[J].地质力学学报,2009,15(2):114~130.PENG Hua,MA Xiumin,JIANG Jingjie.Stability and stress measurement near the Qingchuan fault in the northern LongmenMountains[J].Journal of Geomechanics,2009,15(2):114~130.
[12]王连捷,周春景,孙东生,等.汶川5.12地震引起的库仑应力变化及其对周边地震活动的影响[J].地质力学学报,2008,14(3):193~200.WANG Lian-jie,ZHOU Chun-jing,SUN Dong-sheng,et al.Coulomb stress changes caused by Wenchuan earthquake and itsinfluence on seismic activity in the adjacent area[J].Journal of Geomechanics,2008,14(3):193~200.
[13]谭成轩,孙叶,吴树仁,等.“5.12”汶川MS8.0大地震后关于我国区域地壳稳定性评价的思考[J].地质力学学报,2009,15(2):142~150.TAN Cheng-xuan,SUN Ye,WU Shu-ren,et al.A consideration on regional crustal stability assessment after 5.12 WenchuanMS8.0 strong earthquake in China[J].Journal of Geomechanics,2009,15(2):142~150.
[14]姚鑫,张永双.基于差分干涉雷达的汶川地震同震形变特点[J].地质力学学报,2009,15(2):151~161.YAO Xin,ZHANG Yong-shuang.Co-seismic deformation of 5.12 Wenchuan earthquake based on D-InSAR[J].Journal ofGeomechanics,2009,15(2):151~161.
[15]陈.地壳岩石的力学性能——理论基础与试验方法[M].北京:地震出版社,1988.CHEN Yu.Mechanical properties of crest rock:Theoretical foundation and experimental methods[M].Beijing:SeismologicalPress,1988.
[16]耶格J C,库克N G W.岩石力学基础[M].中国科学院工程力学研究所(译).北京:地震出版,1981.1~690.Jaeger J C,Cook N G W.Fundamentals of rock mechanics[M].Institute of Engineering Mechanics,Chinese Academy ofSciences(Translated).Beijing:Seismological Press,1981.1~690.
[17]Rice J R.Theory of precursory processes in the inception of earthquake rupture[J].Gerlands Beitrage zur Geophysik,1979,88:91~127.
[18]Stuart W D.Quasi-static earthquake mechanics[J].Reviews of Geophysics and Space Physics,1979,17(6):1115~1120.
[19]Goodman R E,Taylor R L,Brekke T L.A model for the mechanics of jointed rock[J].Journal of the Soil Mechanics andFoundations Division,1968,94(3):637~660.
[20]Zienkiewicz O C,Taylor R L.The finite element method(fifth edition)[M].Oxford:Butterworth-Heinemann,2000.
[21]殷有泉,张宏,模拟地震的应变软化的数学模型[J].地球物理学报,1982,25(5):414~423.YIN You-quan,ZHANG Hong.A mathematical model of strain softening in simulating earthquake[J].Acta Geophysica Sinica,1982,25(5):414~423.
[22]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].ActaSeismologica Sinica,1984,6(2):135~145.
[23]殷有泉.非线性有限元基础[M].北京:北京大学出版社,2007.YIN You-quan.Non-linear finite element method[M].Beijing:Peking University Press,2007.
[24]陈运泰,许力生,张勇,等.2008年5月12日汶川特大地震震源特性分析报告[R/OL].http://www.csi.ac.cn/sichuan/chenyuntai.pdf.CHEN Yun-tai,XU Li-sheng,ZHANG Yong,et al.Report of the great Wenchuan earthquake source of May 12,2008[R/OL].http://www.csi.ac.cn/sichuan/chenyuntai.pdf.
[25]安其美,丁立丰,王海忠,等.龙门山断裂带的性质与活动性研究[J].大地测量与地球动力学,2004,24(2):115~119.AN Qi-mei,DING Li-feng,WANG Hai-zhong,et al.Research of property and activity of Longmen Mountain fault zone[J].Journal of Geodesy and Geodynamics,2004,24(2):115~119.
[26]赖锡安,黄立文.中国大陆现今地壳运动[M].北京:地震出版社,2004.LAI Xi-an,HUANG Li-wen.Current crustal movement in Chinese mainland[M].Beijing:Seismological Press,2004.
[27]笠原庆一.地震力学[M].赵仲和(译).北京:地震出版社,1984.Kasahara K.Earthquake mechanics[M].ZHAO Zhong-he(translated).Beijing:Seismological Press,1984.
[28]李海兵,王宗秀,付小方,等.2008年5月12日汶川地震(MS8.0)地表破裂带的分布特征[J].中国地质,2008,35(5):803~813.LI Hai-bing,WANG Zong-xiu,FU Xiao-fang,et al.The surface rupture zone distribution of the Wenchuan earthquake(MS8.0)happened on May 12th,2008[J].Geology in China,2008,35(5):803~813.
[29]李勇,周荣军,Densmore A L,等.青藏高原东缘龙门山晚新生代走滑-逆冲作用的地貌标志[J].第四纪研究,2006,26(1):40~51.LI Yong,ZHOU Rong-jun,Densmore A L,et al.Geomorphic evidence for the Late Cenozoic strike-slipping and thrusting inLongmen Mountain at the eastern margin of the Tibetan Plateau[J].Quaternary Sciences,2006,26(1):40~51.
[30]张培震,徐锡伟,闻学泽,等.2008年汶川8.0级地震发震断裂的滑动速率、复发周期和构造成因[J].地球物理学报,2008,51(4):1066~1073.ZHANG Pei-zhen,XU Xi-wei,WEN Xue-ze,et al.Slip rates and recurrence intervals of the Longmen Shan active fault zone,and tectonic implications for the mechanism of the May 12 Wenchuan earthquake,2008,Sichuan,China[J].Chinese Journalof Geophysics,2008,51(4):1066~1073.
[31]Densmore A L,Ellis M A,LI Yong,et al.Active tectonics of the Beichuan and Pengguan faults at the eastern margin of theTibetan Plateau[J].Tectonics,2007,26,doi:10.1029/2006TC001987.
[32]Burchfiel B C,Royden L H,van der Hilst R D,et al.A geological and geophysical context for the Wenchuan earthquake of 12May,2008,Sichuan,People s Republic of China[J].GSA Today,2008,18(7):4~11.doi:10.1130/GSATG18A.1.
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