Updated predictive equations for broadband (0.01–10 s) horizontal response spectra and peak ground motions, based on a global dataset of digital acceleration records

Abstract

Presented herein is an updated model for empirical prediction of 5 %-damped elastic response spectra in the period range 0–10 s, peak ground acceleration and velocity, based on a global dataset of digital acceleration records. The predictive model features saturation of the shaking parameters with both magnitude $M_{W}$ and distance $R_{ RUP }$, magnitude-dependent distance attenuation, alternative parameterisations of the amplification effects due to local site conditions (based either on ground types or $V_{S,30}$) and corrective terms for style-of-faulting. The calibration dataset comprises more than $1{,}880\times 2$ orthogonal horizontal accelerometer records with $R_{ RUP }< 150$ km from 98 global earthquakes with $4.5\le M_{W}\le 7.9$. The processing technique applied to the acceleration data optimises the reliability of the predictions at long periods, as required by displacement-based design techniques. Developed independently of the recent NGA-West2 and RESORCE-based models, the new predictive tool effectively contributes to capturing the epistemic uncertainties associated with the prediction of seismic shaking levels for engineering applications.