Abstract
This paper shows an example of the grouping of piezocone penetration test (CPTU) characteristics using functional data analysis, together with the results of clustering, in the form of a subsoil rigidity model. The subsoil rigidity model was constructed based on layer separation using the proposed method, as well as the k-means method. In the construction of the subsoil rigidity model, the constrained modulus M was applied. These moduli were determined from empirical relationships for overconsolidated and normally consolidated soils from Poland based on cone tip resistance.