Application of statistics to CPT-based parameter selection

The derivation of representative values for geotechnical parameters accounts for the various sources of uncertainty which are addressed at different stages of the determination process. A comprehensive flow chart for the determination of constitutive model parameters from site tests is proposed. The authors first consider a straightforward methodology to quantify the inherent uncertainty of variables measured from a CPT. An automated framework is then applied to merge outcomes from several transformation functions into a single combined output. This result can be subsequently updated with expert judgment or with direct measurements from laboratory tests using a Bayesian approach. When applied to the friction angle, a reduction of the posterior updated representative standard deviation is observed.