In situ shear wave velocity from multichannel analysis of surface waves (MASW) tests at eight Norwegian research sites

Abstract

Abstract:The Multichannel Analysis of Surface Waves (MASW) technique, used to determine shear wave velocity (V s ) and hence small strain stiffness (G max ), has recently generated considerable interest in the geophysics community. This is because of the ease of carrying out the test and analysis of the data. The objective of this work was to assess the repeatability, accuracy and reliability of MASW surface wave measurements for use in engineering studies. Tests were carried out at 8 wellcharacterised Norwegian clay, silt and sand research sites where V s had already been assessed using independent means. As well as being easy and quick to use MASW gave consistent and repeatable results and for the clay sites the MASW V s profiles were similar to those obtained from other techniques. Reasonable results were also obtained for the silt and sand sites, with the best result being obtained for the finer silt.This work also confirms that MASW V s clay profiles are comparable to those obtained by correlation with CPT. For these sites there also seems to be a good correlation between normalised small strain shear modulus and in situ void ratio or water content and the data fit well with published correlations for clays.

Time-lapse monitoring of climate effects on earthworks using surface waves

“…The dispersion curves extend mostly in the 10-60 Hz frequency band and exhibit an approximate phase velocity range of 225 m/s (at approximately 10 Hz) to 110 m∕s (at approximately 60 Hz). These values are in agreement with other SW phase velocity measurements on wet clays (Foti, 2003;Long and Donohue, 2007). Phase velocity significantly increases at approximately 17 Hz, marking the threshold between frequency components propagating only in the softer embankment (>17 Hz, roughly corresponding to wavelengths <7.25 m, exhibiting lower velocities) and those propagating also through the stiffer subsoil beneath the embankment (<17 Hz, higher velocities).…”

Characterization of Norwegian marine clays with combined shear wave velocity and piezocone cone penetration test (CPTU) data

“…Correlations between G max and e or w Long and Donohue (2007) attempted to relate G max to natural water content (w) or in situ void ratio (e 0 ) for four of the Norwegian clay sites. Note that G max is directly related to V s by:…”

Landform characterization using geophysics—Recent advances, applications, and emerging tools

“…Surface wave methods can be used to determine the textural properties of soils (Long and Donohue, 2007) and shallow subsurface stratigraphy (Watabe and Sassa, 2008). The method has also been employed for the study of karstic terrain and landforms (Thierry et al, 2004;Nasseri-Moghaddam et al, 2007).…”