The Penetration Resistance in a Soil with Well‐defined Structural Units

Abstract Based on both laboratory and in situ probe penetration tests within each horizon of a soil with well‐defined structural units, the magnitude and variability of probe resistance values in relation to probe diameter and structural features are presented. Total penetration resistance was equal for 0.376‐ and 0.514 cm‐diam 60° angle probes; however, the resistance standard deviation and coefficient of variation were larger for the smaller probe. A pocket penetrometer gave significantly larger penetration resistances. There was a close relationship between probe penetration resistance of a 0.376‐cm‐diam probe and root length in natural B 3 horizon.