A SIMPLE ESTIMATION METHOD OF SITE AMPLIFICATION FACTOR AT CENTRAL AND WESTERN DISTRICT OF JAPAN BY USE OF KRIGING METHOD

Abstract

 It is difficult to evaluate site amplification factor analytically because site amplification factor is affected by several factors such as three dimensional deep subsurface profile. Site amplification factors have been evaluated by spectral inversion using strong motion record in the previous study. Therefore, site amplification factor has not been evaluated precisely at sites without strong motion observation.
 This study aims at proposing a simple estimation method of site amplification factors by modifying the amplification factors assuming horizontally layered deep subsurface profile at the site of interest. Amplification factors at low frequencies and peak amplification factors were estimated both by the kriging method and regression equations in terms of peak frequencies of the amplification factors. Applicability of the proposed method was discussed.