Relating Cone Penetrometer Test Information To Geophysical Data: A Case Study

An analysis of data from a recent experiment at Dover Air Force Base (AFB)<br>has revealed a relationship between soil types determined from the mechanical<br>properties measured by cone penetrometer tests (CPT) and the electrical properties that<br>influence geophysical methods. This correlation connects two distinctly different types<br>of physical properties and provides a petrophysical basis for combining information<br>obtained from CPT and geophysical techniques governed by electrical properties. We<br>observed this relationship through the use of semi-logarithmic crossplots of dielectric<br>permittivity versus electrical resistivity where it was found that CPT soil types cluster in<br>a systematic manner to form a linear trend from clay-prone to sand-prone lithologies.<br>We obtained improved segregation of soil types when other factors, such as location<br>relative to the water table and stratigraphy, were used to refine the analyses of these<br>data. In addition, our results indicate that the ratio of permittivity to the logarithm of<br>resistivity is a good geophysical discriminator of the engineering soil classification.