SPT‐CPT Correlations

A method for estimating equivalent Standard Penetration Test (SPT) N‐values from Cone Penetration Test (CPT) data has been presented accounting for variations in soil grain size and SPT energy input. A discussion is given regarding the problems associated with the SPT and how these relate to SPT‐CPT correlations. A historical review of SPT‐CPT correlations is presented with additional recent data that include energy measurements during the SPT. An example is given to illustrate how the SPT data can be rationalized using energy corrections. Also, a chart is provided to estimate mean grain size from CPT data.