Project Abstract
|
Currently, there are relatively few options on the BBP for site amplification. The most commonly used model adjusts the Fourier amplitudes of the time series simulated for rock conditions using either the Campbell and Bozorgnia (2013) or Boore et al. (2013) models. Both of these models were created for response spectra even though they are being applied to Fourier amplitudes. The Shi and Asimaki (2017) model is ready to be implemented; this model combines a Vs profile generator with an analytic nonlinear site response. A model by Hashash et al. (2018) is also under development; this uses the Shi and Asimaki (2017) approach with many randomized profiles to develop average amplitude and phase factors. This approach requires validation, as encountered through similar work in the central and eastern U.S., where bias in the simulations results was encountered for some conditions (Stewart et al. 2017a).
The objective of this project was to develop a Fourier-based empirical site amplification model for use on the SCEC BBP to supplement the above methods. We used data recorded in California and Nevada, but the model was not finalized because the observed nonlinearity was not statistically significant for critical Vs30 bins. We expect this will be resolved in the proposed continuation project (2019 proposal submitted to SCEC) by refining the analysis region, expanding the database of recorded ground motions, and supplementing the analysis with simulations. |
