Joint Occurrence of Spectral Accelerations Between Horizontal and Vertical Ground Motions

This paper estimates the joint occurrence of spectral accelerations (SA) between horizontal (HGM) and vertical ground motions (VGM) based on the NGA-West2 ground motion database, which includes the correlation model and joint distribution model. In this study, the correlation model calculated via CB14 horizontal ground motion prediction equation (GMPE) and BC16 vertical GMPE is obtained. It is verified that the joint distribution of residuals follows a multivariate normal distribution via both a set of quantitative validation methods and a qualitative validation method. Conditional mean spectra of VGMs conditioned on SAs of HGMs are studied as an application of joint occurrence of SA _V–SA _H.