Rapid, cost effective and accurate determination of in situ stiffness using MASW at Bothkennar

The measurement of the small strain shear modulus, Gmax of a soil is important for a range of geotechnical design applications. This usually involves strains of 10-3 % and less. According to elastic theory Gmax can be calculated from the shear wave velocity. Recently several researchers e.g. Donohue et al. (2003, 2004), Long and Donohue (2007) and Park et al. (1999) have shown that Vs (and hence Gmax) can be obtained cheaply and reliably using the Multichannel Analysis of Surface Waves (MASW) method. An opportunity arose to test and further assesses the technique at the UK National soft clay research site at Bothkennar. The purpose of this note is to summarise the data recorded and to compare the resulting Vs measurements to other parallel data.