PHYSICS-BASED SIMULATED ACCELEROGRAMS FOR ENGINEERING APPLICATIONS: THE BB-SPEEDSET

The sparsity of ground motion recordings in the variety of source and site conditions controlling the seismic hazard at a site is still a challenge for several earthquake engineering applications, such as non-linear time history analyses of structural and geotechnical systems. Such issues may prevent a proper definition of the seismic input, especially in near-source conditions and complex geological configurations. With the progress of high-performance computing, physics-based numerical simulations (PBS) have emerged as one of the most promising tools in providing realistic region-and site-specific ground motions where records are lacking. Building confidence in the utilization of regional-scale PBS requires the availability of datasets of simulated accelerograms, subject to a comprehensive validation process, in a broad frequency range, from both seismological and engineering perspectives. This paper aims at presenting an updated version of BB-SPEEDset, a dataset of near-source broadband accelerograms obtained by the spectral element code SPEED (http://speed.mox.polimi.it/) from multiple earthquakes in different geological contexts. To strengthen the potential engineering uses of BB-SPEEDset, firstly, it is shown that the statistical distributions of different ground motion intensity measures, including directivity features, from BB-SPEEDset are in good agreement with those obtained from a near-source records dataset, within the same magnitude and distance range and in a broad range of frequencies. Secondly, illustrative applications of the BB-SPEEDset accelerograms as spectrum-compatible seismic input for non-linear time-history analyses of Single-Degree-Of-Freedom structures and slope stability studies indicate that simulations do not yield biases with respect to record-based analyses.