Influence of Penetration Rate on Measured Resistance with Full Flow Penetrometers in Soft Clay

In recent years full-flow probes, such as the Ball and T-bar penetrometers, have been investigated as alternative in situ tests to the peizocone (CPTu) and the vane shear test (VST). These penetrometers do not require correction for overburden pressure and have the potential to provide more accurate undrained and remolded undrained shear strength measurements in soft sediments. This paper summarizes a portion of a research program that is utilizing a number of highly characterized test sites to comprehensively evaluate aspects of the full flow penetrometers. The results presented herein are used to consider the effect of penetration rate on the determination of the undrained and remolded strength. Twitch and cyclic tests are employed during initial penetration and after cycling. Results are analyzed with respect to normalized velocity for both ball and t-bar full-flow penetrometers.