نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه شهید مدنی آذربایجان، تبریز، ایران
2 پژوهشگر، دانشگاه گیفو، ژاپن
چکیده
در این مطالعه با استفاده از اندازه‌گیری میکروتریمورها در 15 ایستگاه شتابنگاری در شمال‌غرب کشور، فرکانس غالب تعیین شده و بر اساس آن طبقه‌بندی ساختگاه انجام گرفته است. برای این منظور اندازه‌گیری‌ها به مدت 20 شبانه روز انجام گرفتند. پس از تصحیح داده‌های خام، نسبت طیفی مولفه‌ی افقی به مولفه‌ی قائم محاسبه شده و فرکانس متناظر با دامنه‌ی حداکثر به عنوان فرکانس غالب ساختگاه لحاظ گردید. همچنین در 11 ایستگاه با کیفیت مناسب میکروتریمورها، نسبت‌های طیفی میکروتریمورها و رکوردهای زلزله‌ی ثبت شده در ایستگاه‌های شتابنگاری مقایسه شده‌اند. انطباق این دو نسبت طیفی رضایت بخش ارزیابی می‌شود. بر اساس تحلیل میکروتریمورها، حداقل و حداکثر فرکانس به ازای ساختگاه‌های مختلف به ترتیب برابر 72/1 و 34/7 هرتز حاصل شده‌اند. در این مطالعه همچنین با استفاده از مطالعات گذشته، سرعت موج برشی در 30 متر بالایی تعیین و به کمک آیین‌نامه‌های مختلف، نوع خاک ساختگاه‌ها طبقه‌بندی شده‌اند. اگر تقسیم بندی بر اساس فرکانس غالب ساختگاه با تقسیم بندی بر اساس سرعت موج برشی در 30 متر بالایی گزارش شده توسط مرکز تحقیقات راه، مسکن و شهرسازی مقایسه شود، اختلافات قابل توجهی مشاهده می‌شود. این اختلاف می‌تواند ناشی از عدم قطعیت در سرعت موج برشی گزارش شده و هم در فرکانس غالب تخمین زده شده باشد.
کلیدواژه‌ها
کتابنگاری
مرکز تحقیقات راه، مسکن و شهرسازی، 1393- آیین‌نامه طراحی ساختمان‌ها در برابر زلزله (استاندارد 2800)، ویرایش چهارم، 19 ص.
References
Atakan, K., Bard, P. Y., Kind, F., Moreno, B., Roquette, P., Tento, A., Acerra, C., Aguacil, G., Basili, R., Blarel, F., Bordoni, P., Cadet, H., Caserta, A., Cotton, F., Dimitriu, P., Fäh, D., Franco, R., Giulio, G., Grandison, M., Guillier, B., Haghshenas, E., Havskov, J., Koehler, A., Kristek, J., Lacave, C., Maresca, R., Marra, F., Moreno, B., Ohrnberger, M., Oprsal, I., Panou, A., Querendez, E., Richter, G., Roquette, P., Savvaidis, A., Scherbaum, F., Tento, A., Theodulidis, N., Utheim, T., Vidal, S., Vollmer, D., Woessner, J., Wolff, K. and Zacharopoulos, S., 2004- J-sesame a standardized software solution for the H/V spectral ratio technique. 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 2004 Paper No. 2270.
Bard, P. Y. Kind, F., Moreno, B., Roquette, P., Tento, A., Acerra, C., Aguacil, G., Basili, R., Blarel, F., Bordoni, P., Cadet, H., Caserta, A., Cotton, F., Dimitriu, P., Fäh, D., Franco, R., Giulio, G., Grandison, M., Guillier, B., Haghshenas, E., Havskov, J., Koehler, A., Kristek, J., Lacave, C., Maresca, R., Marra, F., Moreno, B., Ohrnberger, M., Oprsal, I., Panou, A., Querendez, E., Richter, G., Roquette, P., Savvaidis, A., Scherbaum, F., Tento, A., Theodulidis, N., Utheim, T., Vidal, S., Vollmer, D., Woessner, J., Wolff, K. and Zacharopoulos, S., 2004- The SESAME project: An overview and main results, in Proceedings, 13th World Conference on Earthquake Engineering, Vancouver, Paper #2207.
Borcherdt, R. D., 1970- Effects of local geology on ground motion near San Francisco Bay, Bull. Seismol. Soc. Am. 60, 29- 61.
Boore, D. M., 2009- TSPP---A collection of FORTRAN program for processing and manipulating time series. USGS, Version 2.0.
Building Seismic Safety Council (BSSC), 2000- The 2000 NEHRP Recommended Provisions for New Buildings and Other Structures, Part I (Provisions) and Part II (Commentary), FEMA 368/369, Washington, D.C.
European Commission, 2004- Guidelines for the Implementation of the H/V Spectral Ratio Technique on Ambient Vibrations; Measurments, Processing and Interpretation, Research General Directorate Project No. EVG1-CT-2000-00026 SESAME.
Field, E. H. and Jacob, K. H., 1995- A comparison and test of various site-response estimation techniques, including three that are not reference-site dependent, Bull. Seismol. Soc. Am. 85, 1127- 1143.
Ghofrani, H., Atkinson, G. M. and Goda, K., 2012- Implications of the 2011 M 9.0 Tohoku Japan earthquake for the treatment of site effects in large earthquakes, Bull Earthquake Eng, Vol. 11, 171- 203.
Gutierrez, C. and Sigh, S. K., 1992- A Site effect Study in Acapolaco, Guerrero, Mexico: Comparison of Results from Strong Ground Motion and Microtremor Data. Bull. Seism. Soc. Am. 82, 642- 659.
Hays, W. W., 1986- Site amplification of earthquake ground motion, Proceedings, 3rd U.S. National Earthquake Engineering Conference, August 24- 28, 1986, Charleston, N.C., Earthquake Engineering Research Institute, 1, 357- 368.
Horike, M., 1985- Inversion of phase velocity of long-frequency microtremors to the S-wave-velocity structure down to the basement in urbanized areas, J. Phys. Earth. 33, 59- 96.
Horike, M., Zhao, B. and Kawase, H., 2001- Comparison of site response characteristics inferred from microtremors and earthquake shear waves, Bull. Seismol. Soc. Am. 91, 1526- 1536.
Japan Road Association, 1980- Specifications for Highway Bridges Part V, Seismic Design, Maruzen Co., LTD.
Japan Road Association, 1990- Specifications for Highway Bridges Part V, Seismic Design, Maruzen Co., LTD.
Kagami, H., Duke, C. M., Liang, G. C. and Ohta Y., 1982- Observation of 1- to 5-second microtremors and their application to earthquake engineering. II. Evaluation of site effect upon seismic wave amplification due to extremely deep soil deposits, Bull. Seism. Soc. Am. 72, 987- 998.
Kagami, H., Okada, S., Shino, K., Oner, M., Darvinski, M. and Mal, A. K., 1986- Observation of 1 to 5 second microtremors and their application to earthquake engineering. Part III. A two-dimensional study of site effects in S. Fernando valley. Bull. Seism. Soc. Am. 76, 1801- 1812.
Kanai, K. and Takana, T., 1954- Measurments of the microtremor. Bulletin of Earthquake Research Institute, Tokyo University, 32, 199- 209.
Kanai, K. and Tanaka, T., 1961- On microtremors VIII. Bull. Earthquake Res. Inst. 39, 97- 114.
Komak Panah, A., Moghaddas, N. H., Ghayamghamian, M. R., Motosaka, M., Jafari, M. K. and Uromieh, A., 2002- Site Effect Classification in East-Central of Iran, Journal of Seismology and Earthquake Enfineering: Spring 2002, Vol. 4, No. 1, 37- 46.
Konno, K. and Ohmachi, T., 1998- Ground-motion characteristics estimated from spectral ratio between horizontal and vertical components of microtremor, Bull. Seism. Soc. Am. 88, 228- 241.
Lachet, C. and Bard, P. Y., 1994- Numerical and theoretical investigations on the possibilities and limitations of Nakamura’s technique, J. Phys. Earth 42, 377- 397.
Lachet, C., Hatzfeld, D., Bard, P. Y., Theodulidis, C. P. and Savvaidis, A., 1996- Site effects and microzonation in the city of Thessaloniki _Greece_: Comparison of different approaches, Bull. Seismol. Soc. Am. 86, 1692- 1703.
Lermo, J. and Chavez-Garcia, F. J., 1994- Are microtremors useful in site response evaluation? Bull. Seismol. Soc. Am. 84, 1350- 1364.
Molnar, S. and Cassidy, F. J., 2006- A comporison of site response technique using weak motion earthquakes and microtremors. Earthquake spectra, 22 (1), 169- 188.
Nakamura, Y., 1989- A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface, Quarterly Reports of the Railway Technical Research Institute 30, 25- 33.
Nogoshi, M. and Igarashi, T., 1970- On the propagation characteristics of microtremors. J. Seism. Soc. Japan, 23, 264-280 (in Japanese with English abstract).
Nogoshi, M. and Igarashi, T., 1971- On the amplitude characteristics of microtremors. J. Seism. Soc. Japan, 24, 24- 40 (in Japanese with English abstract).
Ohta, Y., Kagami, H., Goto, N. and Kudo, K., 1978- Observation of 1- to 5-second microtremors and their application to earthquake engineering. I. Comparison with long-frequency accelerations at the Tokachioki earthquake of 1968, Bull. Seism. Soc. Am. 68, 767- 779.
Okada, H., Matsushima, T. Moriya, T. and Sasatani, T., 1990- An exploration technique using long-frequency microtremors for determination of deep geological structures under urbanized areas, Butsuri-Tansa, 43, 402–417 (in Japanese with English abstract).
Samaei, M., Miyajima, M. and Nojima N., 2016- Attenuation of Fourier Spectra for 2012 Ahar-Varzaghan Double Earthquakes, Northwestern Iran, Journal of Earth and Space Physics, Vol. 41, No. 4, 23- 38.
Satoh, T., Kawase, H. and Matsushima, S., 2001- Differences between site characteristics obtained from microtremors, S-waves, P-waves, and Codas, Bull. Seism. Soc. Am. 91 (2), 313- 334.
Seo, K. and Samano, T., 1992- Application of microtremors to predicting earthquake ground motions, in Summaries of Technical Papers of Annual Meeting, Architectural Institute of Japan, Sendai, Japan. B-2, 107–108 (in Japanese).
Seo, K., 1992- A joint work for measurements of microtremors in the Ashigara valley. Int.
Tokimatsu, K. and Miyadera, Y., 1992- Characteristics of Rayleigh waves in microtremors and their relation to underground structures, J. Struct. Constr. Eng. Trans. Architectural Inst. Japan. 439, 81- 87 (in Japanese with English abstract).
Tokimatsu, K., Nakajo, Y. and Tamura, S., 1994- Horizontal-to-vertical amplitude ratio of short-frequency microtremors and its relation to site characteristics, J. Struct. Constr. Eng. Trans. Architectural Inst. Japan. 457, 11- 18 (in Japanese with English abstract).
Wakamatsu, K. and Yasui, Y., 1995- Possibility of estimation for amplification characteristics of soil deposits based on ratio of horizontal to vertical spectra of microtremors, J. Struct. Constr. Eng. Trans. Architectural Inst. Japan. 471, 61- 70 (in Japanese with English abstract).
Zare, M., Bard, P. Y. and Ghofrany-Ashtiyany, M., 1999- Site Characterizations for the Iranian Strong Motion Network, Soil Dynamics and Earthquake Engineering, Vol. 18, 101- 123.
Zhao, J. X., Irikura, K., Zhang, J., Fukushima, Y., Somerville, P. G., Asano, A., Ohno, Y., Oouchi, T., Takahashi, T. and Ogawa, H., 2006- An empirical site-classification method for strong-motion stations in Japan using H/V response spectral ratio. Bull. Seism. So.c Am. 96, 914- 925.
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