Ground Motion Characteristics Based on Type of Input Motion and Spectral Matching Technique for South Carolina

The selection of input motion and modification (spectral matching) technique for generating acceleration-time history for the dynamic analysis of infrastructure systems is a crucial step. In this study, the effects of the type of input motion (synthetic and real) and the spectral matching (time and frequency domain) techniques on the characteristics of modified motion are investigated for selected sites in South Carolina. The site-specific uniform hazard spectra (UHS) were obtained by performing probabilistic seismic hazard analysis for hard rock site conditions using the Central and Eastern United States Seismic Source Characterization (CEUS-SSC) and NGA-East ground motion models. The synthetic motions were generated using the point-source stochastic model of Atkinson and Boore (1995), and real motions were obtained from the PEER database. The study concluded that the modified ground motion characteristics differ significantly between synthetically generated and real ground motions, also time domain and frequency domain matching techniques. Based on the results, it is recommended to use real motions with the time domain matching technique for generating representative ground motions for South Carolina.