EVALUATION OF SITE AMPLIFICATION FACTORS IN KAMISHIRO DISTRICT, HAKUBA VILLAGE, NAGANO PREFECTURE BASED ON MICROTREMOR MEASUREMENTS WITH HIGH DENSITY

Abstract

 Strong motion due to the 2014 Northern Nagano Prefecture Earthquake (M_J 6.7) caused serious damage to wooden houses in Kamishiro District, Hakuba Village, Nagano Prefecture, Japan. In this study, first, microtremor measurements with high density were carried out at 232 sites in Kamishiro District. The ground shaking characteristics were then evaluated using the microtremor H/V spectra. Based on the empirical relationship between microtremor H/V spectrum and site amplification factor, finally, the site amplification factors from seismic bedrock to ground surface at 232 sites were evaluated. The evaluated site amplification factors will be useful in the strong motion estimation in Kamishiro District.