Abstract
In order to estimate spectral site effect that is essential to prediction of strong motion for local government sites, we examined a relationship between site effect and amplification factor for PGA and JMA seismic intensity obtained at local government sites. A substitute for amplification factor for PGV was evaluated from amplification factor for PGA and JMA seismic intensity. Amplification factors for indices of earthquake ground motion at each observation site were evaluated and relationship between amplification factor and site effect was examined, these have a clear correlation. We proposed a formula in terms of amplification factor for PGA and JMA seismic intensity and clarified that the proposed method can precisely evaluate the site effect. The proposed method make it possible to evaluate the site effect of local government sites that is difficult to obtain the ground motion records and to evaluate the site effect more densely compared with that in the past.
