Influence of seismological factors to earthquake-induced tsunami and sensitivity of structural response to orientations

Abstract

The present paper aims to investigate the implications of the seismological factors (strike angle, rake angle, dip angle, focal depth, and magnitude) on the characteristics (inundation depth/wave height and velocity) of earthquake-induced tsunamis. The uniform slip model is used primarily for characterizing the seismic source and exploring how various seismological factors affect tsunami characteristics. The observed tsunami characteristics is physically explained in far and near fields in light of the seismological factors and wave characteristics. Since unidirectional analysis is generally adopted for tsunami design, sensitivity of structural response to orientations is studied in detail. It has been shown that there exists an orientation that can be determined in terms of pure tsunami characteristics in which the structural response achieves its maximum. Simple case studies are illustrated, and it is shown that, for a deterministic tsunami scenario, the maximum values of inter-story drift may be estimated by a single unidirectional analysis resolving velocity components in the orientation defined herein as the most intense orientation. When assessing structural responses, both uniform and non-uniform slip models are considered simultaneously. Interestingly, although the uniform slip model may provide an unconservative estimate of structural response, it can still accurately predict the orientation that corresponds to the maximum response, similar to the non-uniform slip model.