Practical use of shear wave velocity measurements from SCPTU in clays

The main objective of this paper is to promotes use of shear wave velocity (V_s) measurements from SCPTU testing as a compliment to standard CPTU data. Recent developments in the technique are described. Uncertainties in the methods have been well researched and several methods have been proposed to deal with these uncertainties. Nonetheless V_s measurements seem reliable in isotropic soil conditions. V_s profiles for a range of soft to firm clays world-wide are presented. Clear links between these profiles are identified based on fundamental soil properties. Stiff overconsolidated clays do not follow the same patterns due to pure stress anisotropy and their fissured nature. Correlations between V_s and CPTU data and with a variety of soil properties can be very powerful. However these correlations should ideally be local and only applied to other soils and areas with great caution. An exception might be for correlation between V_s and preconsolidation stress pc’. Use of SCPTU data to help assess sample disturbance and for the prediction of settlement of footings is described. Some future outlooks including dealing with anisotropy are discussed.