Semiempirical model for the estimation of site amplification in Northern South America

Abstract

This article proposes a semiempirical model to estimate seismic site effects based on a predominant-period classification scheme for application in earthquake ground-motion models (GMMs). The proposed model introduces the use of the peak amplitude of the average horizontal-to-vertical ratio of the spectral response of the site obtained from earthquake records. The site effects model is implemented within a GMM estimated using ground-motion records from northern South America. The research compares the performance of the proposed site function with other formulations based on VS30 or site predominant period. This approach yields a smaller within-event variability than alternative methodologies, providing confidence for the reliability of the proposed site classification scheme as a viable alternative for the estimation of site effects, especially for sites for which VS30 measurements are not available.