Effects of impedance ratio between basin sediment and surrounding rock on seismic ground motions and basin-induced Rayleigh waves
-
摘要: 采用综合f-k滤波和基于S变换的极化分析方法,从盆地观测点的模拟时程中提取Rayleigh面波,研究盆地内外介质的阻抗比（IC）对盆地地表地震动及次生面波的影响。结果表明：①此方法能较好地识别和提取Rayleigh面波震相。②盆地放大效应受IR影响显著。水平分量最大放大系数（AFmax）随IC的增加而增大,最大约1.15；垂直分量AFmax随之降低,最大值0.85左右。同时,盆地斜边区域水平分量地震动的削减作用随IC减小而增强。③IC对盆地显著放大区域的分布特征影响明显。IC较小时,盆地内存在多个显著放大区域；IC较大时,此区域仅出现在盆地边缘。④随IC增加,两分量的面波幅值降低,面波持时变长,传播速度增大。⑤IC较小时,面波幅值在盆地内振荡明显,随IC增大,该值在盆地边缘处最大,向内部基本不变。⑥面波幅值与地震动峰值之比在水平分量上随IC增大而降低,最大比值出现在盆地边缘；在垂直分量上受IC影响不明显,主要随与盆地边缘距离的增加而增大。
-
关键词:
- 盆地 /
- Rayleigh面波识别 /
- 阻抗比 /
- 地震动 /
- 放大效应
Abstract: A method for extracting Rayleigh wave phases from simulated seismograms is proposed by incorporating the F-K filtering and polarization analysis based on the time-frequency S transform. Then the effects of impedance ratio (IC) between basin sediment and surrounding rock on the basin ground motion and basin-induced surface wave are investigated. The results show that: (1) The Rayleigh waves can be satisfactorily identified and extracted by using this method. (2) The amplification effects of the basin are significantly affected by IC. The maximum amplification factor (AFmax) of the horizontal component increases with growing IC, with a largest value of about 1.15 for the studied cases. Contrastly, AFmax of the vertical component decreases with larger IC with the largest value of 0.85. In addition, horizontal ground motion at basin slope region is gradually weakened with reduced IC. (3) IC has obvious influences on the distribution features of intensely amplified regions of the basin. Under small IC, a few such regions occur in the basin, however, under large IC, these regions only appear at the basin edge. (4) With increasing IC, the amplitude of the basin-induced Rayleigh waves becomes lower, but the duration gets longer, and their travelling speeds become larger. (5) For the small IC case, an obvious oscillation of the surface wave amplitude (SWA) is observed, whereas for large IC model, the largest SWA only appears near the basin edge, and it is almost unchanged inside the basin. (6) The ratio of SWA to PGD decreases with the growing IC for the horizontal component, and the largest ratio occurs at the basin edge. However, this ratio is insensitive to IC for the vertical component, and it generally increases with larger distance from the basin edge. -
-
![]()
图 1 盆地地表观测点的模拟时程及提取Rayleigh波时程
Figure 1. Simulated seismograms and extracted Rayleigh waves for observation points
![]()
图 2 模拟及提取面波时程的f-k谱
Figure 2. f-k spectra for simulated seismograms and extracted Rayleigh waves
![]()
图 3 二维盆地计算模型（黑色圆点表示代表性的台站位置）
Figure 3. 2D basin model for investigations (solid circles-representative stations)
![]()
图 5 不同阻抗比模型对应的盆地地表观测点水平（左）和垂直(右)分量的模拟位移时程
Figure 5. Time histories of horizontal (left) and vertical (right) components for ground points of different IC models
![]()
图 6 不同阻抗比模型对应的盆地地表观测点的位移峰值分布
Figure 6. PGD distributions for ground points of different IC models
![]()
图 7 不同阻抗比模型对应的盆地地表观测点的放大系数分布
Figure 7. Amplification factor distributions for ground points of different IC models
![]()
图 8 不同阻抗比模型对应的盆地地表观测点Rayleigh面波水平（左）和垂直（右）分量的位移时程
Figure 8. Time histories of Raleigh wave of horizontal (left) and vertical (right) components for ground points of changed IR models
![]()
图 9 不同阻抗比模型的盆地内地表观测点次生Rayleigh面波的位移峰值分布
Figure 9. Amplitude distributions of basin-induced Rayleigh waves for ground points of different IC models
![]()
图 10 IC=0.044模型对应的不同时刻水平分量的位移波场快照（黑色实线之内为盆地）
Figure 10. Snapshots of horizontal component displacement wavefield for IC=0.044 model (black line-basin boundary)
![]()
图 11 不同阻抗比模型的盆地内地表观测点次生Rayleigh面波的幅值与地震动峰值的比值
Figure 11. Distributions of ratio of amplitudes of basin-induced Rayleigh waves to PGDs of ground points for different IC models
表 1 计算模型介质参数
Table 1 Physical parameters of model
类型 剪切波速Vs/(m·s-1) 压缩波速Vp/(m·s-1) 密度/(kg·m-3) 盆地 200~1500 2Vs 1700 基岩 3000 5196 2600 
下载: 导出CSV
表 2 不同阻抗比模型模拟得到的盆地地表水平和垂直分量的PGD最大值及二者的比值
Table 2 Maximum values and ratios of PGDs of horizontal to vertical components of changed IC models
IC 水平分量位移最大值dx/m 垂直分量位移最大值dy/m dy/dx 0.044 4.02 2.99 0.74 0.076 4.23 3.18 0.75 0.109 4.11 3.05 0.74 0.164 3.79 2.22 0.59 0.218 3.62 1.54 0.43 0.327 3.19 0.83 0.26
下载: 导出CSV
-
[1] 刘烁宇, 李英民. 盆地型长周期地震动的判别准则[J]. 湖南大学学报(自然科学版), 2018, 45(5): 85-93. doi: 10.16339/j.cnki.hdxbzkb.2018.05.010 LIU Shuo-yu, LI Ying-min. Discriminant criterion of long-period ground motion in basin[J]. Journal of Hunan University (Natural Science), 2018, 45(5): 85-93. (in Chinese) doi: 10.16339/j.cnki.hdxbzkb.2018.05.010
[2] ANDERSON J G, BODIN P, BRUNE J N, et al. Strong ground motion from the Michoacan, Mexico, Earthquake[J]. Science, 1986, 233(4768): 1043-1049. doi: 10.1126/science.233.4768.1043
[3] KAWASE H. The cause of the damage belt in Kobe: “The basin-edge effect,” constructive interference of the direct S-wave with the basin-induced diffracted/Rayleigh waves[J]. Seismological Research Letters, 1996, 67(5): 25-34. doi: 10.1785/gssrl.67.5.25
[4] 李雪强. 沉积盆地地震效应研究[D]. 北京: 中国地震局工程力学研究所, 2011. LI Xue-qiang. Study on Seismic Effect of Sedimentary Basin[D]. Beijing: Institute of Engineering Mechanics, China Earthquake Administration, 2011. (in Chinese)
[5] YUAN Y F, YANG B P, HUANG S D. Damage distribution and estimation of ground motion in Shidian (China) basin[C]//Proceedings of the International Symposium on the Effects of Surface Geology on Seismic Motion, 1992, Odawara.
[6] ROTEN D, FÄH D, CORNOU C, et al. Two-dimensional resonances in Alpine valleys identified from ambient vibration wavefields[J]. Geophysical Journal International, 2006, 165(3): 889-905. doi: 10.1111/j.1365-246X.2006.02935.x
[7] BOUÉ P, DENOLLE M, HIRATA N, et al. Beyond basin resonance: characterizing wave propagation using a dense array and the ambient seismic field[J]. Geophysical Journal International, 2016, 206(2): 1261-1272. doi: 10.1093/gji/ggw205
[8] LIU Q, YU Y, YIN D, et al. Simulations of strong motion in the Weihe basin during the Wenchuan earthquake by spectral element method[J]. Geophysical Journal International, 2018, 215(2): 978-995. doi: 10.1093/gji/ggy320
[9] FRANKEL A, HOUGH S, FRIBERG P, et al. Observations of Loma Prieta aftershocks from a dense array in Sunnyvale, California[J]. Bull Seism Soc Am, 1991, 81(5): 1900-1922. doi: 10.1785/BSSA0810051900
[10] ABRAHAM J R, LAI C G, PAPAGEORGIOU A. Basin-effects observed during the 2012 Emilia earthquake sequence in Northern Italy[J]. Soil Dynamics and Earthquake Engineering, 2015, 78: 230-242. doi: 10.1016/j.soildyn.2015.08.007
[11] 王季. 基于F-K变换的井下多道瑞利波频散曲线提取[J]. 煤田地质与勘探, 2012, 40(2): 75-77. https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201202020.htm WANG Ji. Dispersive curve extraction of Rayleigh wave in coal mine based on F-K transform[J]. Coal Geology and Exploration, 2012, 40(2): 75-77. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MDKT201202020.htm
[12] 雍凡, 罗水余, 李颜贵, 等. F-K变换与预测反褶积压制多次波效果对比[J]. 物探化探计算技术, 2014, 36(6): 700-707. https://www.cnki.com.cn/Article/CJFDTOTAL-WTHT201406010.htm YONG Fan, LUO Shui-yu, LI Yan-gui, et al. Comparisons of F-K domain methods and prediction deconvolution for multiple attenuation[J]. Computing Techniques for Geophysical and Geochemical Exploration, 2014, 36(6): 700-707. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-WTHT201406010.htm
[13] PINNEGAR C R. Polarization analysis and polarization filtering of three-component signals with the time-frequency S transform[J]. Geophysical Journal International, 2006, 165(2): 596-606. doi: 10.1111/j.1365-246X.2006.02937.x
[14] GALIANA-MERINO J J, PAROLAI S, ROSA-HERRANZ J. Seismic wave characterization using complex trace analysis in the stationary wavelet packet domain[J]. Soil Dynamics and Earthquake Engineering, 2011, 31(11): 1565-1578. doi: 10.1016/j.soildyn.2011.06.009
[15] MEZA-FAJARDO K C, PAPAGEORGIOU A S, SEMBLAT J F. Identification and extraction of surface waves from three-component seismograms based on the normalized inner product[J]. Bulletin of the Seismological Society of America, 2015, 105(1): 210-229. doi: 10.1785/0120140012
[16] MEZA-FAJARDO K C, PAPAGEORGIOU A S. Estimation of rocking and torsion associated with surface waves extracted from recorded motions[J]. Soil Dynamics and Earthquake Engineering, 2016, 80: 225-240. doi: 10.1016/j.soildyn.2015.10.017
[17] MEZA-FAJARDO K C, VARONE C, LENTI L, et al. Surface wave quantification in a highly heterogeneous alluvial basin: case study of the Fosso di Vallerano valley, Rome, Italy[J]. Soil Dynamics and Earthquake Engineering, 2019, 120: 292-300. doi: 10.1016/j.soildyn.2019.02.008
[18] ZHANG Z, SUN Y, BERTEUSSEN K. Analysis of surface waves in shallow water environment of the Persian Gulf using S and t-f-k transform[M]//SEG Technical Program Expanded Abstracts 2010. Society of Exploration Geophysicists, 2010: 3723-3727.
[19] WANG C, WANG Y. Ground roll attenuation using polarization analysis in the t-f-k domain[J]. Geophysical Journal International, 2017, 210(1): 240-254. doi: 10.1093/gji/ggx152
[20] NARAYAN J P. Effects of angle of incidence of SH-wave at the basin-edge on the characteristics of basin edge induced Love wave[J]. J Earthq Tsunami, 2012, 6(1): 1250006. doi: 10.1142/S1793431112500066
[21] NARAYAN J P. Effects of P-wave and S-wave impedance contrast on the characteristics of basin transduced Rayleigh waves[J]. Pure and Applied Geophysics, 2012, 169(4): 693-709. doi: 10.1007/s00024-011-0338-7
[22] LIU Q, YU Y, ZHANG X. Three-dimensional simulations of strong ground motion in the Shidian basin based upon the spectral-element method[J]. Earthquake Engineering and Engineering Vibration, 2015, 14(3): 385-398.
[23] MOCZO P, KRISTEK J, BARD P Y, et al. Key structural parameters affecting earthquake ground motion in 2D and 3D sedimentary structures[J]. Bulletin of Earthquake Engineering, 2018, 16(6): 2421-2450.
[24] 李一琼. 基于SDSCD数值算法完善与盆地表征模型模拟[D]. 北京: 中国地震局地球物理研究所, 2014. LI Yi-qiong. The Numerical Algorithm Perfection of SDSCD and Simulation on Basin Characteristic Model[D]. Beijing: Institute of Geophysics, China Earthquake Administration, 2014. (in Chinese)
[25] 刘中宪, 黄磊, 梁建文. 三维局部场地对地震波的散射IBIEM-FEM耦合模拟[J]. 岩土工程学报, 2017, 39(2): 301-310. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201702017.htm LIU Zhong-xian, HUANG Lei, LIANG Jian-wen. FEM-IBIEM coupled method for simulating scattering of seismic waves by 3-D complex local site[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(2): 301-310. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201702017.htm
[26] 廖振鹏. 工程波动理论导论[M]. 北京: 科学出版社, 2002. LIAO Zhen-peng. Introduction to Wave Motion Theories in Engineering[M]. Beijing: Science Press, 2002. (in Chinese)
计量
- 文章访问数: 239
- HTML全文浏览量: 29
- PDF下载量: 83
