Simulation of strong ground motions modified by attenuation effects under specific soil conditions: modeling the 2017 Puebla, Mexico (Mw 7.1) earthquake

Abstract

This research presents an updated scheme of simulation for strong ground motions based on stochastic summation methods and the source-to-site attenuation effects under particular soil conditions different from firm sites. Two approaches are proposed to modify and improve the empirical Green’s functions at different source distances from seismic station records: (1) a spectral shape based on far-field point-source spectra models and (2) through specific ground motion prediction equations (GMPEs) and random vibration theory (RVT). The ground motions simulated were compared with the September 19, 2017 Mexico records (normal-fault-intraslab event, Mw 7.1), finding that for soft soils, it will be possible to reproduce some characteristic of spectral peaks appropriately in high frequency compared with available similar approaches or using one-dimensional wave propagation models. On average, the spectral overestimations from available simulation approaches and for high-frequency bandwidth (i.e., 0.2 s and 0.3 s) can be reduced by a factor between 2 and 5 using proper attenuation corrections; this effect could be especially beneficial for small structures and low-rise buildings where the inertial design forces will be potentially reduced.