Joint inversion of surface wave dispersion and HVSR curves using one station

![CDATA[The inversion of Rayleigh dispersion curve has been used to estimate the Vs ground profiles (thickness of soil layers vs. shear wave velocity, Vs) of a site. These Rayleigh dispersion curves are usually retrieved using several geophones or sensors set up in linear array for active methods (e.g., MASW), or linear array (ReMi) and/or geometrical array for passive methods. However, it is known that rough ground models without detailed characterisation of the very shallow layers can be estimated only when the Rayleigh dispersion inversion is carried out. In recent years, the inversion of Horizontal to Vertical Spectral Ratio (HVSR) of passive microtremor records has become popular because only one station consisting of a 3 component sensor (one vertical and two horizontal components) is needed to carry out the field measurements. According to the results reported by several researchers, a more detailed estimation of shallow layers might be obtained when the HVSR inversion is applied. However, supplementary field surveys, such as CPT test, are needed to obtain reliable HVSR inversions, meaning that the characterisation of surface layers without supplementary geotechnical surveys are estimated with some uncertainties and should be avoided. In this paper, a method is presented to obtain ground models combining the joint inversion of Rayleigh wave dispersion and the HVSR curves. The surface wave dispersion curves are obtained using two methods. As case study, passive microtremor measurements and surface wave testing using both active techniques, the MASW and the one using only one station, are carried out at a dynamically compacted area of the Penrith Lakes site. From the results obtained at this site, a detailed Vs ground model resembling CPT record was obtained.]]