Characterisation of Norwegian marine clays with combined shear wave velocity and CPTU data

A database of research quality CPTU and shear wave velocity
information for Norwegian marine clays has been assembled so as to study the small
strain stiffness relationships for these materials and to examine the potential use of
CPTU and Vs data in combination for the purposes of characterising these soils. Data
for sites where high quality block sampling was carried out have mostly been used.
Improvements have been suggested to existing correlations between Gmax or Vs and
index properties for these soils. Recent research has shown that CPTU qt and
especially u2 and Vs can be measured reliably and repeatably and are not operator or
equipment dependant. Therefore a new soil classification chart involving Qt and
normalised shear wave velocity (Vs1) or Vs1 and Δu/σv0' is presented. Using this chart
it is possible to clearly distinguish between clays of different OCR.