ABSTRACT
Many people interpret soil properties from CPTU measurements based on correlations embedded in software packages without ever questioning the validity of those correlations. This could be termed the ‘black box’ approach! This paper aims to show how dangerous this can be but also the power of the CPTU in helping to show the variations in soil properties within profiles. Based on correlations properties can be both over and under-estimated, which can of course result in both unsafe design and over design. Too often one correlation must be used to derive a soil property required in another correlation, further compounding the potential for errors. A range of sites will be examined with a range of soils varying from very soft clays and silts to stiff clays, sands and soft rocks.
