Study of Site Effects in Kobe Area Using Microtremors
In this study, an attempt was made to examine the effect of site conditions on damage distribution in the Kobe City area, after the Hyogo-ken Nanbu earthquake of Jan. 17, 1995, using measured microtremors. A preliminary measurement of microtremors was done between Feb. 18 and 21, 1995. Based on the findings of the preliminary measurement, a more detailed investigation was made between March 4 and 6, 1995. In both cases continuous-stationary measurements and mobile measurements were made. The measured microtremors in the Kobe area showed site-dependent variation in time history, spectral amplitude, spectral ratio, and predominant period. Stiff soil sites showed lower values of amplitude both in time history and spectral amplitude, while soft and deep soil formations showed higher values. The predominant periods also varied in relation to the soil formation in some of the cases. The damage distribution of building structures, especially that of low-rise structures including wooden houses, showed good relation with the characteristics of measured microtremors.
- Journal of physics of the earth
Journal of physics of the earth 45(2), 121-133, 1997-04
The Seismological Society of Japan, The Volcanological Society of Japan , The Geodetic Society of Japan