芦山地震地震动上下盘效应研究
|
摘要
2013年4月20日的芦山7.0级地震是继2008年5月12日汶川8.0级特大地震之后,发生在龙门山断裂带上的又一次大震级逆冲型地震。与汶川地震相比,芦山地震的发震断层没有地表出露,断层的滑动角更大,其逆冲性质更强烈。本文挑选了芦山地震中断层距小于200km的45条强震动记录,基于地震动衰减关系进行统计分析,对比了上盘和下盘台站地震动参数相对于衰减关系的对数残差。结果表明:芦山地震的上下盘效应明显,近断层上盘地震动的高频成分要高于同断层距的下盘;上盘地震动衰减要明显快于下盘。地震动衰减关系用简单的一个距离参数很难描述近场断层尺寸效应的影响,也很难模拟地震动上下盘效应。因此,在近场强地面运动模拟中,应多考虑有限断层模型,以模拟断层的尺寸效应。
Lushan MS7.0 earthquake on 20 th April, 2013 is another thrust fault generated earthquake occurred at Longmen Mountain Fault Zone after 2008 Wenchuan MS8.0 earthquake. Compared with Wenchuan earthquake, the rupture of seismogenic fault of Lushan earthquake did not reach the ground, and had a greater rake angle. Based on ground motion attenuation model, this paper we chosen 45 strong motion records with rupture distance less than 200 km, to analyze the logarithmic residuals of ground motion data at sites of the hanging wall and the foot wall. The results show that the attenuation model overall underestimate the ground motion at the hanging wall, especially for the high frequency component of ground motion; ground motion in the hanging wall attenuated with increasing rupture distance more quickly than that at the foot wall. A simple parameter, such as rupture distance, is not efficient enough to describe the influence of fault size to the near-fault ground motion attenuation. As a result, we should consider the finite fault model in the near field strong ground motion simulation.
Lushan MS7.0 earthquake on 20 th April, 2013 is another thrust fault generated earthquake occurred at Longmen Mountain Fault Zone after 2008 Wenchuan MS8.0 earthquake. Compared with Wenchuan earthquake, the rupture of seismogenic fault of Lushan earthquake did not reach the ground, and had a greater rake angle. Based on ground motion attenuation model, this paper we chosen 45 strong motion records with rupture distance less than 200 km, to analyze the logarithmic residuals of ground motion data at sites of the hanging wall and the foot wall. The results show that the attenuation model overall underestimate the ground motion at the hanging wall, especially for the high frequency component of ground motion; ground motion in the hanging wall attenuated with increasing rupture distance more quickly than that at the foot wall. A simple parameter, such as rupture distance, is not efficient enough to describe the influence of fault size to the near-fault ground motion attenuation. As a result, we should consider the finite fault model in the near field strong ground motion simulation.
引文
王栋,谢礼立,胡进军,2008.倾斜断层不对称分布引起的几何效应——上下盘效应.地震学报,30(3):271—278.
王栋,2010.近断层地震动的上下盘效应研究[博士学位论文].中国地震局工程力学研究所.
谢祖军,金笔凯,郑勇,葛粲,熊熊,熊诚,许厚泽,2013.近远震波形反演2013年芦山地震震源参数.中国科学:地球科学,43(6):1010—1019.
俞言祥,高孟潭,2001.台湾集集地震近场地震动的上盘效应.地震学报,23(6):615—621.
张勇,许力生,陈运泰,2013.芦山“4.20”地震破裂过程及其致灾特征初步分析.地球物理学报,56(4):1408—1411.
Abrahamson N.A.and Silva W.J.,2008.Summary of the Abrahamson and Silva NGA ground motionrelations.Earthquake Spectrum,24:67—98.
Abrahamson N.A.and Somerville P.G.,1996.Effects of the hanging wall and footwall on ground motions recordedduring the Northridge earthquake.Bull.Seism.Soc.Am.,86(1B):93—99.
Boore D.M.and Atkinson G.M.,2008.Ground-motion prediction equation for the average horizontal componentof PGA,PGV,and 5%-Damped PSA at spectral periods between 0.01s and 10s.Earthquake Spectrum,24:99 —138.
Boore D.M.,Lamprey J.W.and Abrahamson N.A.,2006.Orientation-Independent measures of groundmotion.Bull.Seism.Soc.Am.,96(4A):1502—1511.
Campbell K.and Bozorgnia Y.,2008.NGA ground model for the geometric mean horizontal component of PGA,PGV,PGD and 5%-Damped linear elastic response spectra for periods ranging from 0.01 to 10s.EarthquakeSpectrum,24:139—172.
Chang T.Y.,Cotton F.,Tsai Y.B.and Angelier J.,2004.Quantification of hanging-wall effect s on ground motion:some insights from the 1999 Chi-Chi earthquake.Bull.Seism.Soc.Am.,94(6):2186—2197.
Chiou B.and Youngs R.B.,2008.An NGA model for the average horizontal component of Peak Ground motion and Response Spectra.Earthquake Spectrum,24:173—216.
王栋,2010.近断层地震动的上下盘效应研究[博士学位论文].中国地震局工程力学研究所.
谢祖军,金笔凯,郑勇,葛粲,熊熊,熊诚,许厚泽,2013.近远震波形反演2013年芦山地震震源参数.中国科学:地球科学,43(6):1010—1019.
俞言祥,高孟潭,2001.台湾集集地震近场地震动的上盘效应.地震学报,23(6):615—621.
张勇,许力生,陈运泰,2013.芦山“4.20”地震破裂过程及其致灾特征初步分析.地球物理学报,56(4):1408—1411.
Abrahamson N.A.and Silva W.J.,2008.Summary of the Abrahamson and Silva NGA ground motionrelations.Earthquake Spectrum,24:67—98.
Abrahamson N.A.and Somerville P.G.,1996.Effects of the hanging wall and footwall on ground motions recordedduring the Northridge earthquake.Bull.Seism.Soc.Am.,86(1B):93—99.
Boore D.M.and Atkinson G.M.,2008.Ground-motion prediction equation for the average horizontal componentof PGA,PGV,and 5%-Damped PSA at spectral periods between 0.01s and 10s.Earthquake Spectrum,24:99 —138.
Boore D.M.,Lamprey J.W.and Abrahamson N.A.,2006.Orientation-Independent measures of groundmotion.Bull.Seism.Soc.Am.,96(4A):1502—1511.
Campbell K.and Bozorgnia Y.,2008.NGA ground model for the geometric mean horizontal component of PGA,PGV,PGD and 5%-Damped linear elastic response spectra for periods ranging from 0.01 to 10s.EarthquakeSpectrum,24:139—172.
Chang T.Y.,Cotton F.,Tsai Y.B.and Angelier J.,2004.Quantification of hanging-wall effect s on ground motion:some insights from the 1999 Chi-Chi earthquake.Bull.Seism.Soc.Am.,94(6):2186—2197.
Chiou B.and Youngs R.B.,2008.An NGA model for the average horizontal component of Peak Ground motion and Response Spectra.Earthquake Spectrum,24:173—216.
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