HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Matsunami, K. Articles by Xie, L.-l. Search for Related Content GeoRef GeoRef Citation

Estimation of Seismic Site Response in the Tangshan Area, China, Using Deep Underground Records

Disaster Prevention Research Institute
Kyoto University
Gokasho, Uji
Kyoto, 611-0011, Japan
matunami{at}egmdpri01.dpri.kyoto-u.ac.jp
(K.M., K.I.)

Institute of Engineering Mechanics
China Seismological Bureau
9 Xuefu Road
Harbin, China
(W.Z., L.X.)

Site amplification in the Tangshan area, China, was analyzed using records of small events (M_L 2.9–4.4) observed by a strong motion array with a deep (–822 m) underground station deployed between 1982 and 1984 following the 1976 Tangshan earthquake. The effect of destructive interference at the underground site due to surface reflections was confirmed to be negligible in this case. The source, propagation path, and site effects were separated simultaneously by linear inversion using the underground reference site. The S-wave quality factor was found to be approximated by the relation 29f ^0.9 in the frequency range 1–10 Hz. The conventional surface rock reference site was found to have a characteristic frequency-dependent site effect, which increased markedly from the theoretical amplification factor of 2 over the frequency range of interest. A reference-independent technique assuming an -squared source model was also introduced and produced results that were in good agreement with the results obtained using the underground reference. The reference-independent technique revealed the underground station to have a nearly flat response consistent with the theoretical response, indicating that an underground or borehole bedrock site is a better reference than a surface rock for seismic hazard analysis. The reference-independent technique produced accurate absolute site amplification factors for the area examined in this study, demonstrating the usefulness of the method for site effect analysis.