Effects of Earthquake Source Recurrence on the Conditional Seismic Hazard Analysis

Abstract

<p>In earthquake engineering, the selection of input ground motions for nonlinear structural dynamic analysis is an important element in performance based structural design. Probabilistic seismic hazard analysis (PSHA) provides a basis for determination of ground motion characteristics by incorporating regressions on ground motion metrics from past recorded earthquakes for known seismic sources, propagation paths and local site conditions. Due to aleatoric variability in the processes of fault rupture, seismic wave propagation, and local site response; and, the epistemic uncertainty in models of these phenomena due in part to limited data, there exist uncertainties in seismic hazard assesments. This uncertainty should be interpreted carefully before the resulting ground motion predictions are adopted for dynamic analysis and design of structures. This thesis examines the sensitivity of algorithmic parameters and the choice of earthquake magnitude recurrence relations on the conditional ground motion characteristics. For this purpose, new correlation coefficients between pseudo-spectral acceleration (PSA), peak ground velocity (PGV), and cumulative absolute velocity (CAV) are derived using data from the PEER-NGA earthquake database. Finally, the sensitivity of the conditional mean spectrum to earthquake recurrence models is investigated. It is concluded that the choice of the Gutenberg-Richter or Characteristic Magnitude model can significantly affect the conditional mean spectra.</p>