The current tool is an implementation of Casagrande’s plasticity chart (1948). It is used to classify fine-grained soils using their plasticity characteristics as expressed by the Plasticity Index (IP) and Liquid Limit (LL).

Samples with high plasticity tend to be clay-based materials, samples with low plasticity tend to be silt-based materials, and samples with no plasticity tend to have little or no silt or clay.

This tool derives soil stratigraphy from CPT or CPTU data using both non-normalized (pre-1990) and normalized Soil Behavior Type (SBT) indices proposed by Robertson. By interpreting cone resistance, sleeve friction, and pore pressure data (where available), the tool identifies changes in soil behavior with depth.

The method offers a data-driven approach to interpreting subsurface layering and can complement borehole investigations, particularly in sites with limited sampling or where continuous profiling is beneficial.