Spectrum-compatible synthetic time histories for Central and Eastern US using a new hybrid ground motion simulation technique


Synthetic ground motion generation is a proper approach for high seismicity regions such as Central and Eastern US (CEUS) while suitable real earthquake records in terms of magnitude, site characteristics, and distance are scarce. To perform time history analysis of structures, building and bridge design seismic provisions require at least three or seven recorded or synthetic earthquakes. In this study, we generate a suite of appropriate spectrum-compatible synthetics through a proposed hybrid broadband (HBB) simulation technique for CEUS. In a proposed interdisciplinary engineering and seismological approach, we apply different kinematic parameters, which are correlated with different intensity measures in engineering application (such as peak ground acceleration, velocity, displacement: PGA, PGV, PGD, etc.) as well as a spatial random field model to characterize the complexity of the slip distribution on a non-homogeneous fault. Long period synthetics are obtained through a kinematic modeling of the source and deterministic wave propagation using a discrete wavenumber-finite element method. We use the point source stochastic method of Boore (2005) to generate high frequency portion of the time series. Finally, the broadband synthetics are obtained implementing a pair matched low-pass and high-pass Butterworth filters applied on the long and low frequency synthetics, respectively. A case study is presented and the results are shown for the predefined scenario of Mw=6.5. The proposed method is compared with the ground motion prediction equations proposed for the region.

Publication Title

NCEE 2014 - 10th U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering