Assessment of Coefficient of Variation (CV) and Correlation Length (CL) using Horizontal to Vertical Spectral Ratios (HVSR) inversion

Abstract

This project aims to determine the Coefficient of Variation (CV) and Correlation Length (CL) of the soil at site. Themethodology involves data acquisition through seismometers, analysis of horizontal to vertical spectral ratios (HVSR), inversion analyses to obtain shear wave velocity (VS) profiles, and subsequent calculations of CV and CL. The site consists of a dense array of 14 seismometers, complemented by additional borehole tests. HVSR were computed for both surface and subsurface recordings, and the resulting inversed VS profiles were utilized to derive a representative profile for the site. CV was computed for each layer of the representative profile, and CL was determined from spatial autocorrelation coefficients. The analysis revealed that CV varies with depth, with higher values in shallow layers and a decrease with depth. The CL also exhibited depth-dependent behavior, increasing up to 150 m and decreasing beyond that depth. This comprehensive investigation provides valuable insights into the soil properties at site, which are essential for seismic hazard assessments and engineering considerations.