利用不同方法估算流动台站的场地响应

摘要/Abstract

摘要： 本文以2003年7月21日云南大姚6.2级地震序列为例, 分别利用地面运动反演法(Moya方法)、水平与垂直向之比法(Nakamura方法)和参考台站法研究大姚地区场地响应特征。主要结论有: ① Moya方法计算的场地响应结果表明, 大姚地区场地的放大作用是比较明显的, 平均在3~20倍, 最高达到40倍; 卓越频率位于3~6 Hz之间, 但在高频处(约10 Hz以上)场地响应衰减得比较明显; 不同岩性台基的台站, 其场地响应结果存在一定的差别, 台基为风化砾岩的场地响应结果比较平缓, 其场地响应值比台基为土层的其他台站小一些。② 入射角在40°以上和以下范围, Nakamura方法得到的场地响应形态有差异, 但在各自范围内, 场地响应与入射角的依赖关系不明显。③ 利用同一台站不同时间记录到的地震资料, 由三种方法各自得到的场地响应都具有较好的稳定性; 由于垂直分量仍具有放大作用(在10 Hz以下), Moya的结果大于Nakaruma的结果, 但两者形态上一致性较好; 参考台站法由于受参考台站的影响, 计算得到的场地响应形态和其他两种方法差异较大。④ Moya方法是依赖于震源模型的方法, 它能给出绝对的场地响应值, 其它两种方法的结果是一种相对场地响应, 受参考对象的影响较大。

关键词: 场地响应, 大姚地震序列, 流动台站

Abstract: Site response characteristics in Dayao area were analyzed using various methods such as ground-motion-inversion method (Moya′s method) and horizontal-to-vertical-spectral ratio (Nakamura′s method) and reference-site method, using the records of earthquake sequences of the 21 July 2003 Dayao (M6.2), Yunnan province. Our results show that ① Site response results by Moya′s method indicate that the site amplifications in the Dayao area are apparent, between 3 and 20 times, up to 40 times at the most. The dominant frequency is between 3 and 6 Hz, but the site responses decay very fast at the high frequency (≥10 Hz). There are some differences among the site responses for the stations with different rock base. Site responses appear more flat for the stations with efflorescent conglomerate base and their values are smaller than other stations with soil base. ② Site responses by Nakamura′s method with the angle of incidence bigger or smaller than 40°appear to be different, but with no obvious dependence on the angle of incidence in its own ranges. ③ Site responses by these three methods with the seismic data recorded by the same station in different times appear to have good stability. Site responses by Moya′s method are bigger than that of Nakamura′s method at the frequency <10 Hz due to the existing of amplification in the vertical component, but their forms are coherent. ④ Moya′s method is a source-dependent approach to estimate absolute site effects and the other two methods are reference-dependent approaches to obtain relative site effects and are deeply affected by the reference site.

Key words: Site response, Dayao earthquake sequence, Temporary station

中图分类号:

P315

华卫, 陈章立, 郑斯华. 利用不同方法估算流动台站的场地响应[J]. 地震, 2010, 30(3): 30-44.

HUA Wei, CHEN Zhang-li, ZHENG Si-hua. Estimation of Site Responses for Temporary Stations Using Various Methods[J]. EARTHQUAKE, 2010, 30(3): 30-44.

参考文献

[1] Shearer P M. Introduction to Seismology[M]. New York: Cambridge University Press, 1999.
[2] Moya C A, Aguirre J, Irikura K. Inversion of source parameters and site effects from strong ground motion records using genetic algorithms[J]. Bull Seism Soc Amer, 2000, 90(4): 977-992.
[3] Jin A, Moya C A, Ando M. Simultaneous determination of site response and source parameters of small earthquakes along the Atotsugawa fault zone[J]. Bull Seism Soc Amer, 2000, 90(6): 1430-1445.
[4] Nakamura Y A. Method for dynamic characteristics estimation of subsurface using microtremor on the ground surface[J]. QR Railway Tech Res Inst, 1989, 30: 25-33.
[5] Onder C K, Sinan I N. A comparative study on the actual and estimated seismic response of Kiralkizi Dam in Turkey[J]. J earthqu eng, 2005, 9: 445-460.
[6] Borcherdt R D. Effects of local geology on ground motion near San Francisco Bay[J]. Bull Seism Soc Amer, 1970, 60: 29-61.
[7] Boore D M, Joyner W B. Site amplications for generic rock sites[J]. Bull Seism Soc Amer, 1997, 87(2): 327-341.
[8] Boore D M. Simulation of ground motion using the stochastic method[J]. Pure and Applied Geophysics, 2003, 160: 635-675.
[9] Brune J N. Tectonic stress and the spectra of seismic waves from earthquakes[J]. J Geophys Res, 1970, 75: 4997-5009.
[10] Brune J N. Correction[J]. J Geophys Res, 1971, 76: 5002.
[11] Atkinson G M, Mereu R F. The shape of ground motion attenuation curves in Southeastern Canada[J]. Bull Seism Soc Amer, 1992, 82: 2014-2031.
[12] Lermo J F, Francisco S, Chavez-Garcia J. Site effect evaluation using spectral ratios with only one station[J]. Bull Seism Soc Amer, 1993, 83(5): 1574-1594.
[13] Field E H, Jacob K H. A comparison and test of various site response estimation techniques, including three that are non reference-site dependent[J]. Bull Seism Soc Amer, 1995, 85(4): 991-1005.
[14] Castro R R, Pacor F, Sala A, et al. S wave attenuation and site effects in the region of Friuli, Italy[J]. J Geophys Res, 1996, 101: 22355-22369.
[15] Castro R R, RESNOM Working Group. P and S-wave site response of the seismic network RESNOM determined from earthquakes of Northern Baja California, Mexico[J]. Pure Appl Geophys, 1998, 1052: 125-138.
[16] Bard P Y. Microtremors measurements a tool for site effect estimation?[A]. ESG 98 symposium[C], 1998.
[17] 陶夏新, 刘曾武, 郭明珠, 等. 工程场地条件评定中的地脉动研究[J]. 地震工程与工程振动, 2001, 21(4): 18-23.
[18] Andrews D J. Objective determination of source parameters and similarity of earthquakes of different size[J]. Geophysical Monographs, 1986, 37(6): 259-267.
[19] Parolai S, Bindi D, Baumbach M, et al. Comparison of Different Site Response Estimation Techniques Using Aftershocks of the 1999 Izmit Earthquake[J]. Bull Seism Soc Amer, 2004, 94: 1096-1108.
[20] Tsujiura M. Spectral analysis of the coda waves from local earthquakes[J]. Bull Earthquake Inst Univ Tokyo, 1978, 53: 1-48.
[21] Phillips W S, Aki K. Site amplification of coda waves from local earthquakes in central California[J]. Bull Seism Soc Amer, 1986, 76: 627-648.
[22] Margheriti L, Wennerberg L, Boatwright J. A comparison of　coda and S-wave spectral ratios as estimates of site response in the southern San Francisco Bay Area[J]. Bull Seism Soc Amer, 1994, 84: 1815-1830.
[23] Su F, Aki K. Site amplification factor in central and southern California determined from coda waves[J]. Bull Seism Soc Amer, 1995, 85: 452-466.
[24] Jin A, Fukuyama E. Seismic Energy for Shallow Earthquakes in Southwest Japan[J]. Bull Seism Soc Amer, 2005, 95: 1314-1333.
[25] 张天中, 马云生, 张焕生, 等. 震源谱的尾波多台多震综合求解方法[J]. 地球物理学报, 1997, 40(5): 702-709.
[26] 张天中, 马云生, 黄蓉良. 震源、衰减和场地因子的单台尾波解法[J]. 地震学报, 1998, 20(2): 137-143.
[27] Aki K, Chouet B. Origin of coda waves: source, attenuation and scattering effects[J]. J Geophys Res, 1975, 80: 3322-3342.
[28] 华卫, 刘杰, 郑斯华, 等. 2003年云南大姚6.2级、 6.1级地震序列特征分析及地震触发研究[J]. 中国地震, 2006, 22(1): 10-23.
[29] Papageorgiou A S and Aki K. A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion, part Ⅱ: Applications of the model[J]. Bull Seism Soc Amer, 1983, 73(4): 953-978.
[30] Yoshimoto K, Sato H, Yoshihisa I, et al. Frequency-dependent attenuation of P and S waves in the Kanto area, Japan, based on the coda-normalization method[J]. Geophys J Int, 1993, 114: 165-174.
[31] Chung T W, Sato H. Attenuation of high-frequency P and S waves in the crust of Southeastern Korea[J]. Bull Seism Soc Amer, 2001, 91 (6): 1867-1874.
[32] Satoh T, Kawase H, Sato T. Evaluation of local site effects and their removal from borehole records observed in the Sendai region, Japan[J]. Bull Seism Soc Amer, 1995, 85(6): 1770-1789.
[33] Lachet D, Hatzfeld C, Bard P Y, et al. Site effects and microzonation in the city of Thessaloniki(Grece): comparison of different approaches[J]. Bull Seism Soc Amer, 1996, 86(6): 1692-1703.
[34] Theodulidis N, Archuleta R J, Bard P Y, et al. Horizontal to vertical spectral ratio and geological conditions: the case of Garner Valley downhole array in southern California[J]. Bull Seism Soc Amer, 1996, 86(2): 306-319.
[35] Bonilla L F, Steidl J H, Lindley G T, et al. Site amplification in the San Fernando Valley, California: variability of site-effect estimation using the S-wave, coda, and H/V methods[J]. Bull Seism Soc Amer, 1997, 87(3): 710-730.
[36] Dimitriu P P, Papaioannou C A, Theodulidis N P. EUROSEISTEST strong-motion array near Thessaloniki, northern Greece: a study of site effects[J]. Bull Seism Soc Amer, 1998, 88(3): 862-873.
[37] Tsuboi S, Saito M, Ishihara Y. Verification of horizontal to vertical spectral ratio technique for estimation of site response using borehole seismographs[J]. Bull Seism Soc Amer, 2001, 91(3): 499-510.
[38] Castro R R, Pacor F, Bindi D, et al. Site Response of Strong Motion Stations in the Umbria, Central Italy, Region[J]. Bull Seism Soc Amer, 2004, 94(2): 576-590.
[39] Malagnini L, Mayeda K, Akinci A, et al. Estimating Absolute Site Effects[J]. Bull Seism Soc Amer, 2004, 94(4): 1343-1352.
[40] Matsunami K, Zhang W B, Irikura K, et al. Estimation of Seismic Site Response in the Tangshan Area, China, Using Deep Underground Records[J]. Bull Seism Soc Amer, 2003, 93: 1065-1078.
[41] Anderson J G, Hough S. A model for the shape of the Fourier　amplitude spectrum of acceleration at high frequencies[J]. Bull Seism Soc Amer, 1984, 74(5): 1969-1994.
[42] Steidl J H, Tumarkin A G, Archuleta R J. What is a reference site?[J]. Bull Seism Soc Amer, 1996, 86: 1733-1748.