BB-SPEEDset: A Validated Dataset of Simulated Earthquake Ground Motions for Engineering Aims

Physics-based numerical simulations (PBS) are recognized as one of the most promising tools for providing earthquake ground motions in the source and site conditions which are poorly sampled by records, such as in the near-source region of severe shocks and in complex geological conditions. This undersampling issue is likely to persist into the future, in spite of the ever increasing number of seismic networks providing high-quality recordings, and it often prevents a proper characterization of seismic input for earthquake engineering applications. The key to strengthen and broaden the engineering utilization of PBS is the availability and dissemination of datasets of simulated broadband accelerograms, which have passed rigorous validation tests from both seismological and engineering perspectives. This paper aims at presenting a validated dataset of broadband near-source earthquake ground motions from 3D PBS-named BB-SPEEDset-obtained by the spectral element code SPEED (http://speed.mox.polimi.it/). BB-SPEEDset (v1.0) includes around 12,000 broadband accelerograms obtained from the simulation of several earthquakes in a wide range of magnitude (MW = 5.5-7.4), faulting styles and geological contexts. The main validation tests on BB-SPEEDset (v1.0) are illustrated in order to verify that: (a) the features and statistical distributions of earthquake ground motions are consistent with those obtained from a near-source records dataset, within the same magnitude and distance range; and (b) BB-SPEEDset accelerograms, when used to provide spectrum-compatible input motions for inelastic time-history analyses of structures, do not yield any systematic bias in terms of engineering demand parameters with respect to those obtained using recorded base motions.