A Study on the Response Instability of Seismically Isolated Structures Affected by Ground Inclination During Earthquakes Part 1 : Estimation of Ground Inclination During Earthquakes and the Influence of Static Ground Inclination
Mitsuo Miyazaki and Yukihiro Nishimura
Dynamic Design Inc., ISE Building 3F, 1-16 Sumiyoshi-cho, Shinjuku-ku, Tokyo, Japan
Seismic isolation can provide superior building safety and dynamic performance during strong earthquakes, however, it is known that some near-source ground motions produce excessive response deformations, which may be larger than the allowable capacity of the isolation devices. Isolation systems with longer periods and higher damping are more capable of resisting such deformations, and the author proposed new isolation systems with periods of 10 sec, or even longer. Longer isolation periods, however, mean less resistance and restoring force in the isolation systems, which may cause concerns about unstable response characteristics during strong earthquakes. One such unstable behavior is the possibility of excessive horizontal displacements of the isolation system resulting from ground inclination. Based on numerical analyses using existing vertical ground motion records, this paper estimates the ground inclination during earthquakes and studies the anticipated horizontal deformation of isolated structures that might be induced by such ground inclination.
-  “Recorded Earthquake Ground Motions in the 2007 Niigata-ken Chuetsuoki Earthquake and the 2008 Iwate-Miyagi Nairiku Earthquake,” No.5 Technical Annual Report, pp. 2-2∼2-9, Input motion sub-committee, Seismic Isolation Design Div., JSSI (the Japan Society of Seismic Isolation), 2009/4/23.
-  M. Miyazaki, “The Next Generation of Seismic Isolation, – Going beyond Seismic Design Dominated by Earthquakes –,” J. of Disaster Research Vol.3, No.6, Dec., 2008.
-  S. Winchester, “A Crack in the Edge of the World, America and the Great California Earthquake of 1906,” (Japanese Edition 2006) Hayakawa Publishing, Inc.
-  P. L. Fradkin, “The Great Earthquake and Firestorms of 1906,” University of California Press, pp. 52-54, 2005.
-  G. Hansen and E. Condon, “Denial of Disaster, The Untold Story and photographs of the San Francisco earthquake and Fire of 1906,” Cameron and Company, 1989.
-  W. Bronson, “The Earth Shook, The Sky Burned,” Chronicle Books, pp. 24-25, April, 1986.
-  “Earthquakes and Foundation stones,” The commemorative booklet of retirement lecture by Prof. Isao Toriumi, convivial meeting surrounding Prof. Isao Toriumi, pp. 12-24, 1989/11.
-  “Interview video tapes to persons who experienced the 1948 Fukui earthquake (40 years anniversary project, unedited version),” NHK Fukui, 1988.
-  K. Seo and T. Samano, “Lessons Learned from the 1948 Fukui Earthquake,” The 19th Symposium on ground Vibrations (1991), Architectural Institute of Japan, p.15, 1991.7.26.
-  M. J. Pender and T. W. Robertson, “Edgecombe Earthquake : Reconnaissance Report,” Bulletin of the New Zealand National Society for Earthquake Engineering, Vol.20, No.3, pp. 202 and 210-212, September, 1987.
-  “The Imperial Valley, California, earthquake of October 15, 1979,” Geological Survey Professional Paper 1254, USGS, 1982.
-  R. L. Porcella, R. B. Matthieesen, and R. P. Maley, “Strong-Motion Data Recorded in the United States,” (above 11, pp. 289-317, p. 291).
-  G. N. Bycroft, “EL CENTRO Differential Ground Motion Array,” (above 11, pp. 351-356).
-  “Reconnaissance Report IMPEIAL VALLEY, CALIFORNIA, EARTHQUAKE October 15, 1979,” Earthquake Engineering Research Institute, Feb., 1980.
-  “Geotechnical Investigations at Strong-Motion Stations in the Imperial Valley, California,” United States Department of the Interior Geological Survey, Open-File Report 84-562, pp. 99 and 161, Aug., 1984.
-  S. Midorikawa, “Lessons Learned from the 1979 Imperial Valley Earthquake,” The 13th Symposium on ground Vibrations (1985), Architectural Institute of Japan, pp. 77-86, 1985.7.9.
-  “Seismic-Refraction Studies of the Imperial valley Region, California, Profile Models, a Traveltime Contour Map, and a Gravity Model,” United States Department of the Interior Geological Survey, Open-File Report 81-270.
-  M. Saito, “The Theory of SeismicWave Propagation,” pp. 155-160, University of Tokyo Press, 2009.7,27.
-  S. Senna et al., “Microtremor survey and Surface velocity structure model in the Ojiya and Kawaguchi region,” Japan geoscience union meeting 2005, S101-P020, 2005.
-  S. Senna et al., “Study on Earthquake Damage for Niigataken-Chuetsu Earthquake (Part1) Microtremor survey and Surface velocity structure model in the Ojiya and Kawaguchi region,” Summaries of technical papers of annual meeting, AIJ (Architectural Institute of Japan), pp. 147-150, Sept., 2005.