Estimation on site effect from different techniques using aftershocks of Chi-Chi earthquake

doi:10.7523/j.issn.2095-6134.2009.3.012

Abstract

Abstract:

Site effects are analyzed for the Chelongpu fault area using the aftershock strong-motion data of the 1999 Chi-Chi, Taiwan, earthquake. Four techniques are used including traditional spectral ratios of S wave, generalized inversion technique, receiver function of S wave and genetic algorithm. Our results show that the predominant frequencies for each site estimated by these four methods are almost the same. However, the site amplifications for each site obtained by these methods have some differences. The results of generalized inversion technique and the traditional spectral ratio method are affected by the reference site. After corrected by the site effect of the reference site obtained by genetic algorithm, the corrected results of the generalized inversion technique agree well with the results of genetic algorithm. This shows that genetic algorithm is a reasonable technique to estimate the absolute site effect for a site. In this study, usually, the site amplification obtained by the method of the receiver function is larger than other three techniques. Considering there are still many unclear issues in this method, we suggest that one should be very careful when using receiver function to estimate the site effect. Finally, we gave the Q_S-value calculated by generalized inversion technique. It is frequency dependent, Q_S=69.7f?^0.73, in the range of frequency 0.4~20Hz.

Key words: site effects, Chi-Chi earthquake, reference site, predominant frequency, genetic algorithm

CLC Number:

P315.9

OUYANG Xing-Yan, ZHANG Wen-Bo, ZHANG You-Bing. Estimation on site effect from different techniques using aftershocks of Chi-Chi earthquake[J]. , 2009, 26(3): 373-382.

References

[1] Parolai S, Bindi D, Baumbach M, et al. Comparison of different site response estimation techniques using aftershocks of the 1999 Izmit earthquake. BSSA, 2004, 94(3): 1096~1108

[2] Borcherdt RD. Effects of local geology on ground motion near San Francisco Bay. BSSA, 1970, 60(1): 29~61

[3] Andrews DJ. Objective determination of source parameters and similarity of earthquakes of different size. Earthquake Source Mechanics, 1986, 6: 259~267

[4] Steidl JH, Tumarkin AG, Archuleta RJ. What is a reference site? BSSA, 1996, 86(6): 1733~1748

[5] Nakamura Y. A method for dynamic characteristics estimations of subsurface using microtremors on the ground surface. Quarterly Rep RTRI, Jpn, 1989, 30: 25~33

[6] Chavez-Garcia FJ, Dominguez T, Rodriguez M, et al. Site effects in a volcanic environment: A comparison between HVSR and array techniques at Colima, Mexico. BSSA, 2007, 97(2): 591~604

[7] Moya A, Aguirre J, Irikura K. Inversion of source parameters and site effects from strong ground motion records using genetic algorithms. BSSA, 2000, 90(4): 977~992

[8] Zhang WB,Xie LL,Guo MZ.Estimation on site-amplification from different methods using strong motion data obtained in Tangshan,China.Acta Seismologica Sinica,2001,23(6):604~614(in Chinese) 章文波,谢礼立,郭明珠.利用强震记录分析场地的地震反应.地震学报,2001,23(6):604~614

[9] Matsunami K, Zhang WB, Irikura K, et al. Estimation of seismic site response in the Tangshan area, China, using deep underground records. BSSA, 2003, 93(3): 1065~1078

[10] Field EH, Jacob KH. A comparison and test of various site-response estimation techniques, including three that are not reference-site dependent. BSSA, 1995, 85(4): 1127~1143

[11] Parolai S, Bindi D, Augliera P. Application of the generalized inversion technique (GIT) to a microzonation study: numerical simulations and comparison with different site-estimation techniques. BSSA, 2000, 90(2): 286~297

[12] Assimaki D, Li W, Steidl JH, et al. Site amplification and attenuation via downhole array seismogram inversion: A comparative study of the 2003 Miyagi-Oki aftershock sequence. BSSA, 2008, 98(1): 301~330

[13] Shin TC, Kuo KW, Lee WHK, et al. A preliminary report on the 1999 Chi-Chi (Taiwan) earthquake. Seismological Research Letters, 2000, 71(1): 24~30

[14] Lee WHK, Shin TC, Kuo KW, et al. CWB free-field strong-motion data from the 921 Chi-Chi earthquake: processed acceleration files on CD-ROM, strong-motion data series CD-001. Taipei: Seismological Observation Center, Central Weather Bureau, 2001

[15] Lee CT, Cheng CT, Liao CW, et al. Site classification of Taiwan free-field strong-motion stations. BSSA, 2001, 91(5): 1283~1297

[16] Souriau A, Roulle A, Ponsolles C. Site effects in the city of Lourdes, France, from H/V measurements: Implications for seismic-risk evaluation. BSSA, 2007, 97(6): 2118~2136

[17] Lermo J, Chavez-Garcia FJ. Site effect evaluation using spectral ratios with only one station. BSSA, 1993, 83(5): 1574~1594

[18] Lee WHK, Shin TC, Kuo KW, et al. CWB free-field strong-motion data from the 21 September Chi-Chi, Taiwan, earthquake. BSSA, 2001, 91(5): 1370~1376

[19] Huang HC, Yang YT, Huang CC. Site response evaluation using the H/V ratio at the Yan-Liau station in Hualien, Taiwan. Pure Appl Geophys, 2002, 159: 2715~2731

[20] Zhang WB,Zhou YN,Xie LL.Estimation of absolute site amplification. Earthquake Engineering and Engineering Vibration,2001,21(4):1~9(in Chinese) 章文波,周雍年,谢礼立.场地放大效应的估计.地震工程与工程振动,2001,21(4):1~9