Single- and multi- component inversion of Rayleigh waves acquired by a single 3-component geophone: an illustrative case study

0482504 - ÚSMH 2018 RIV CZ eng J - Journal Article
Dal Moro, Giancarlo - Puzzilli, L.M.
Single- and multi- component inversion of Rayleigh waves acquired by a single 3-component geophone: an illustrative case study.
Acta geodynamica et geomaterialia. Roč. 14, č. 4 (2017), s. 431-444. ISSN 1214-9705. E-ISSN 2336-4351
Institutional support: RVO:67985891
Keywords : surface wave analysis * Rayleigh wave dispersion * joint inversion * Vs30
OECD category: Volcanology
Impact factor: 0.886, year: 2017

Rayleigh wave dispersion can occur according to complex mode excitation such that the interpretation of the phase or group velocity spectra can be erroneous thus leading to wrong reconstruction of the subsurface shear-wave velocity profile. In this paper, we present a case study solved by considering the holistic analysis of the Rayleigh waves recorded by a single three-component (3C) geophone and inverted by considering the group-velocity spectra of the radial and vertical components together with the Radial-to-Vertical Spectral Ratio (RVSR) and the RPM (Rayleigh-wave Particle Motion) frequency curve. In order to test the performance of the considered methodologies, we intentionally considered a complex site characterized by a high level of background noise and with a limited space to perform the investigation. In addition, passive data collected by the same 3C geophone are used to compute the Horizontal-to-Vertical Spectral Ratio (HVSR). Due to the vibrations produced by a nearby excavator, in order to obtain a meaningful HVSR we selected only a small portion of the recorded data. Computed HVSR is then jointly inverted with the active data to further validate the retrieved subsurface model and obtain information about the shear-wave velocities of the deeper layers. Altogether, four different inversion strategies are pursued and the obtained VS profiles compared also with the data available from local penetrometer test and borehole information.
Permanent Link: http://hdl.handle.net/11104/0277996