Prediction Equations for Ground‐Motion Significant Durations Using the NGA‐West2 Database

Significant duration is an important parameter in seismic risk assessment. In this article, new prediction equations for significant duration parameters are developed using a recently compiled Next Generation Attenuation‐West2 (NGA‐West2) database. The use of the greatly expanded NGA‐West2 database improves the model predictions for small‐to‐moderate magnitude and far‐source earthquake scenarios. The new model has a functional form with only four predictor variables, namely the moment magnitude ( M w), rupture distance ( R rup), time‐averaged shear‐wave velocity in the top 30 m ( V S 30), and depth to the top of the rupture ( Z tor). A magnitude‐dependent aleatory variability term is also proposed. The new model can be used to estimate significant durations for earthquake scenarios with moment magnitude M w from 3 to 7.9 and rupture distance up to 300 km. The proposed model has been systematically compared with some existing prediction models. In addition, empirical correlations between significant durations and spectral accelerations have been studied using the proposed model and the NGA‐West2 database.