Model validations, comparisons, and issues of the Next Generation Attenuation (NGA) relations for predicting earthquake ground motions.

摘要

Recent earthquake ground motion prediction equations, such as those developed from the Next Generation Attenuation of Ground Motions (NGA) project in 2008, have established a new baseline for the estimation of ground motion parameters such as peak ground acceleration (PGA ), peak ground velocity (PGV), and spectral acceleration (Sa). When these relations were published, very little was written about model validation or prediction accuracy. We perform statistical goodness-of-fit analyses to quantitatively compare the predictive abilities of these recent models, using several testing subsets of the master database used to develop the NGA models. In addition, we perform a blind comparison of the new models with previous simpler models, using ground motion records from the two most recent earthquakes of magnitude 6.0 or greater to strike mainland California. A model validation framework is introduced to assess the prediction accuracy of ground motion prediction equations and aid in their future development.