Calibration of cone resistance in a sand with fines by means of model testing

Cone penetrometer tests (CPTU) are used extensively for offshore soil characterization. There are estab-lished correlations between CPTU parameters and relative density (Dr) for clean sand, but studies on Dr cor-relations for sand with fines content are not well-exposed. As part of a Joint Industry Project (CSi), a dedi-cated program for CPT-based Dr correlation calibration has been carried out in a large calibration chamber (CC) and a centrifuge calibration chamber (CCC) using Ticino sand with different amount of fines (FC = 0, 15% and 30%). The CPTUs have been performed at two relative density levels (Dr ~50% and ~80%) with σ’v between 50 kPa and 200 kPa in normally consolidated samples. Both CC and CCC tests show that the cone resistance reduces as a function of increasing fines content. The Jamiolkowski et al. (2003) correlation, initially developed for clean sand, has been recalibrated for Ticino sand with fines based on CC and CCC tests. Recommendation and limitations of the Dr correlation for sand with fines content are discussed.