Broad-band ground motions combining low-frequency deterministic simulations and high frequency scatterograms: validation against the 1994 Northridge earthquake

Walter Imperatori (ETHZ), Dr. K. Olsen (SDSD, USA), Dr. P. Martin Mai, (KAUST, Saudi Arabia)

Broadband scenario ground motions (0-10 Hz) play an important role in seismic hazard analysis, and accurate broadband synthetics are needed for performance-based earthquake engineering analysis. Validation and verification of the broadband methods is critical to ensure realistic synthetic seismograms. In this study we present a validation of the most recent version of the ETH/SDSU broadband method against strong-motion data from the 1994 Northridge earthquake. The synthetics are compared to data using the bias of the response spectral residuals, as well as a goodness-of-fit measure recently proposed. We also test two different approaches to estimate frequency-dependent site amplification factors.

_{Figure: Bias of the response spectral residuals for broadband synthetics.}