Assess the effects of loading rate and interface roughness on T-bar penetration resistance

Abstract

A recently developed sequential limit analysis method was employed to look into the large displacement penetration behaviour of T-bar penetrometers in soft clay, considering the effects of strain softening and strain rate. Close attention was paid to the effects of interface roughness and the strain rate on the penetration response, before reaching an ideal full-flow state, in order to shed some light on the improved estimate of the in situ strength of surficial soil. The validity of the model was confirmed through a comparison of two small-scale laboratory tests and one centrifuge test, followed by a parametric study in which a T-bar was penetrated from the soil surface to a depth of over five diameters. Analytical equations were derived to assess the effects of interface roughness, viscosity parameter and penetration rate on the T-bar penetration resistance.