Evaluation of variability of shear wave velocity in India

Abstract

The shear wave velocity is a significant component in seismic hazard studies. This involves standard practice in seismic hazard analysis through ground motion prediction equations (GMPEs), ground response analyses (GRAs), or the computation of amplification factors. In practice, the shear wave velocity may be obtained through invasive methods, noninvasive methods, transformation models, or correlation-based methods. Currently, the uncertainty component of shear wave velocity has either been overlooked or oversimplified. The aim was to quantify the range of variations in shear wave velocity across India. The database included data of reported shear wave velocities in 20 states collected from various project reports and publications. A brief review of the methods used to obtain the data is given, along with a systematic highlight of the range of uncertainties encountered and their statistics. Base-case profiles for response analyses are recommended, and their statistics are examined. These observations aid computation of amplification factors. The transformation uncertainties of the shear wave velocity and the standard penetration test (SPT) were examined. The outcomes of the research will guide reliable seismic hazard studies across countries. Furthermore, this study paves the way for future development toward addressing uncertainties in shear wave velocity and facilitates the use of reliability-based design procedures.