Algorithm for generation of stratigraphic profiles using cone penetration test data

Cone Penetration Test (CPT) data are often used directly in the design of shallow and deep foundations and many other applications. To produce more cost-effective designs, it is advantageous to use CPT data to establish stratigraphic profiles as well. Algorithms to generate a stratigraphic profile using data from an individual CPT sounding and a Soil Behavior Type (SBT) chart as inputs are presented. Two SBT charts from the literature were selected and modified to eliminate ambiguity in soil classification. Novel algorithms were developed for handling the occurrence of thin layers within a stratigraphic profile to account for the fact that the standard CPT cone cannot accurately sense layers with thickness below a certain limit and a representative cone resistance cannot be obtained if the layer is too thin. Likewise, the algorithms prevent the creation of a soil profile with adjacent layers of essentially the same soil by consolidating layers appropriately. The algorithms presented generate a design soil profile, produced using a precise classification based on soil type and state and by elimination of artificial layering, that can be more effectively used in design.