Experience with CPTU, T-bar and ball penetrometers in two soft clays.

Field developments in deep waters with very soft soils have led to increased reliance on the use of in situ tests to evaluate soil design parameters. Recently the T-bar and ball penetrometers have been introduced due to their potential for increasing the reliability of interpreted undrained shear strength relative to the CPTU for soft clays. Empirical correlations based on field tests and laboratory tests on samples at two onshore soft clay sites indicate that T-bar correlation factors are in a somewhat narrower range compared to cone factors. Recommendations are given in terms of cone and T-bar factors to use.