BB-SPEEDset: A Validated Dataset of Broadband Near-Source Earthquake Ground Motions from 3D Physics-Based Numerical Simulations

Abstract

\n This article introduces a strong-motion dataset of near-source broadband earthquake ground motions from 3D\xa0physics-based numerical simulations—named BB-SPEEDset—obtained by the code SPEED (SPectral Elements in Elastodynamics with Discontinuous Galerkin)—developed at Politecnico di Milano, Italy. Taking advantage of the earthquake ground-motion scenarios produced so far by SPEED, in most cases validated against earthquake recordings, the main objective of this work is to construct and validate a dataset of simulated broadband waveforms to be used as a support for characterization and modeling of near-source earthquake ground motions. To pursue this objective, the following steps were necessary, namely: (1)\xa0the implementation of an effective workflow suitable to process in an homogeneous format various SPEED simulations; (2)\xa0the generation of broadband time histories using a technique based on artificial neural networks, trained on strong-motion records; (3)\xa0the creation of a flat file collecting, for each simulated scenario, the most relevant metadata (fault rupture scenario, site response proxies, source-to-site distances) as well as a comprehensive set of ground-motion intensity measures of the processed broadband waveforms (peak ground acceleration, velocity and displacement, spectral ordinates, duration, pulse period, etc.). Finally, a comprehensive set of consistency checks is made to verify the absence of any systematic bias in the trend of the BB-SPEEDset results with respect to the NEar-Source Strong-motion (NESS) version 2.0 near-source recorded ground-motion dataset. Indeed, the main features of near-source ground motion in BB-SPEEDset, ranging from the statistical distributions of peak and integral measures both at short and long periods, the ground-motion attenuation with distance, to the features of impulsive ground motions and directionality effects, are in substantial agreement with those from NESS.