A generic shear wave velocity profiling model for use in ground motion simulation

This study presents a generic model for constructing shear-wave velocity (VS) profiles for various conditions that can be used for modeling the upper-crustal modification effects in ground motion simulations for seismic hazard analysis. The piecewise P-wave velocity (VP) profiling model is adopted in the first place, and the VS profile model is obtained by combining the VP profiling model and VS/VP model. The used VS/VP model is constructed from various field measurements, experimental data, or CRUST1.0 data collected worldwide. By making the best use of the regionally/locally geological information, including the thickness of sedimentary and crystalline layers and reference VS values at specific depths, the VS profile can be constructed, and thus the amplification behavior of VS for a given earthquake scenario can be predicted. The generic model has been validated by four case studies of different target regions world around. The constructed profiles are found to be in fair agreement with field recordings. The frequency-dependent uppercrustal amplification factors are provided for use in stochastic ground motion simulations for each respective region. The proposed VS profiling model is proposed for region-specific use and can thus make the ground motion predictions to be partially non-ergodic.