MASW? A critical perspective on problems and opportunities in surface-wave analysis from active and passive data (with few legal considerations)

0571768 - ÚSMH 2024 RIV GB eng J - Journal Article
Dal Moro, Giancarlo
MASW? A critical perspective on problems and opportunities in surface-wave analysis from active and passive data (with few legal considerations).
Physics and Chemistry of the Earth. Roč. 130, JUN 2023 (2023), č. článku 103369. ISSN 1474-7065. E-ISSN 1873-5193
Institutional support: RVO:67985891
Keywords : Surface Waves * Rayleigh waves * Love wavesgroup velocities * MASW (Multichannel Analysis of Surface Waves) * FVS (Full Velocity Spectrum) analysis
OECD category: Volcanology
Impact factor: 3.7, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.pce.2023.103369

In the last two decades, surface wave analysis has become a widespread practice for several geotechnical ap-plications and the MASW (Multichannel Analysis of Surface Waves) acronym has become extremely popular. The standard MASW approach is based on the personal (i.e. subjective) interpretation of the phase-velocity spectrum of the vertical component of Rayleigh waves. This way, we do not invert the actual datum but a subjective interpretation that can be wrong and lead to erroneous shear-wave velocity (VS) profiles. Even in case data interpretation is correct, non-uniqueness of the solution obtained from inversion of just one observable remains a problem. A series of active and passive synthetic and field datasets are used to illustrate main issues in surface wave analysis and highlight the need for multi-component analysis possibly according to an approach that goes beyond the subjective interpretation of modal dispersion curves. The multi-component approach considered to overcome the ambiguities of single-component analysis is performed according to the FVS (Full Velocity Spec-trum) approach, therefore overcoming subjective velocity-spectra interpretations. It is also shown that surfacewave analysis can be effectively carried out considering not phase velocities but group velocities, with the obvious benefit that while for the phase-velocity analysis multi-offset data are necessary, the definition of the group velocities can be accomplished from single-offset data (i.e. from the data of one single sensor). An example of erroneous VS determination made for an important public building is illustrated in order to highlight the importance of multi-component analysis and the need for stricter guidelines.
Permanent Link: https://hdl.handle.net/11104/0342869