- Article
- Open access
- Published:
Variation process in stiffness inferred by nonlinear inversion during mainshocks at Kushiro Port vertical array site
Earth, Planets and Space volume 60, pages 581–589 (2008)
Abstract
In the present study, a set of three strong motions accompanied by 21 before and after mainshock motions from liquefied soil at the Kushiro Port vertical array site have been obtained. S-wave velocity variation is estimated using a new proposed nonlinear GA inversion technique. This inversion technique is reproductive in assessment for S-wave velocities due to its direct link with the simulation FEM program and matching technique between the observed and simulated waveforms. Layers (6 ∼ 23 m depth) have been found to be responsible for liquefaction at the Kushiro Port site. Stiffness degradation due to liquefaction could be predicted by applying the inversion technique on the horizontal components of the mainshocks at different time-windows and then multiplying the weighting functions by the nonlinear simulated ground motions. These weighting functions were applied to delete the misfit time window of the nonlinear simulated ground motions when these were compared to the observed records. Finally, stacking was applied for the weighted nonlinear simulated ground motions. A strong degree of liquefaction is concluded during the Kushiro-Oki (1993) and the Hokkaido Toho-Oki (1994) earthquakes, whereas a low degree of liquefaction was detected to have occurred during the Tokachi-Oki (2003) earthquake due to high increase of rigidity following a trend that resembles a consolidation curve.
References
Aguirre, J. and K. Irikura, Nonlinearity, Liquefaction, and velocity variation of soft soil layers in Port Isalnd, Kobe, during the Hyogo-ken Nanbu Earthquake, Bull. Seismol. Soc. Am., 87, 1244–1258, 1997.
Coley, D. A., An Introduction to Genetic Algorithms for Scientists and Engineers, World Scietific, 2001.
Coley, D. A., David Coley’s GA: http://www.ex.ac.uk/cee/ga/software.htm, 2002.
Koketsu, K., K. Hikima, S. Miyazaki, and S. Ide, Joint Inversion of Strong Motion and Geodetic Data for the Source Process of the 2003 Tokachi-oki, Hokkaido, Earthq., Earth Planets Space, 55, 1–6, 2003.
Kokusho, T. and M. Matsumoto, Nonlinearity in site amplification and soil properties during the 1995 Hyogo-Ken Nanbu Earthquake, Special Issue of Soils and Foundations, Japanese Geotechnical Society, 1–9, Sept. 1998.
Kostadinov, M. and F. Yamazaki, Detection of soil liquefaction from strong motion records, Earthq. Eng. Struct. Dyn., 173–193, 2001.
Miyajima, M., M. Kitaura, and S. Nozu, Detective method of liquefaction using strong ground motion records, Proceedings of the 3rd ChinaJapan-US Trilateral Symposium on Lifeline Earthquake Engineering, Kunming, China, 133–140, August 1998.
Nakayama, W., Y. Shimizu, and T. Suzuki, A new method to detect subsoil liquefaction using seismic records, Proceedings of the 53rd Annual Conference of Japanese Society of Civil Engineers, vol. 1-B. JSCE, 862–863, 1998 (in Japanese).
Ozaki, R., Study on real-time earthquake mitigation liquefaction monitoring and earthquake countermeasures, PhD Thesis, Kobe University, 1999 (in Japanese).
Pease, J. W. and T. D. O’Rourke, Seismic response of liquefaction sites, J. Geotech. Geoenviron. Eng., 123, 37–45, 1997.
Pestana, J. M. and F. Nadim, AMPLE2000 A computer program for analysis of amplification of earthquakes, Geotechnical Engng. Report No. UCB/GT/2000-04, Department of Civil & Environ. Engineering, University of California, Berkeley, 2000.
Pyke, R., Non-linear soil models for irregular cyclic loadings, J. Geotech. Eng. Div., ASCE, 105(GT6), 715–726, 1979.
Qian, Sh. and D. Chen, Joint Time-Frequency Analysis: Methods and Applications, Prentice-Hall PTR: Upper Saddle River, NJ, 1996.
Seed, H. B., R. T. Wong, E. M. Idriss, and K. Tokimatsu, Moduli and Damping Factors for Dymanic Analyses of Cohesionless Soils, Report No. UCB/EERC-84/11, Erathquake Engineering Research Center, University of California, Berkeley, 1984.
Terzaghi, K., Theoretical Soil Mechanics, Wiley, New York, 1956.
Thabet, M., H. Nemoto, and K. Nakagawa, Reliability of shear wave velocity models inferred from linear site response analyses using log data, J. Geosci., Osaka City Univ., 50, Art. 9, p. 107–123, March 2007.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Thabet, M., Nemoto, H. & Nakagawa, K. Variation process in stiffness inferred by nonlinear inversion during mainshocks at Kushiro Port vertical array site. Earth Planet Sp 60, 581–589 (2008). https://doi.org/10.1186/BF03353121
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1186/BF03353121