Geotechnical characterisation and engineering properties of Burswood clay

The Burswood clay is a lightly overconsolidated and sensitive silty clay of high to extremely high plasticity. In two extensive characterisation studies, a wide range of in situ tests were carried out at the Burswood site, including full-flow penetrometer tests (T-bar, ball and plate). In addition, thin-wall tube samples and high-quality Sherbrooke block samples were collected for laboratory testing. The stress–strain–strength, consolidation and compressibility characteristics of Burswood clay were investigated, and the performance of various penetrometers in characterising the soft Burswood clay was assessed. The paper compares values of stiffness and shear strength measured by different in situ and laboratory tests, quantifying the degree of non-linearity of the stress–strain response, the effect of sample disturbance on the measured mechanical properties, the degree of strength anisotropy, and the influence of strain rate on the measured shear strength. In addition, factors relating the net penetration resistance measured by cone, T-bar and ball penetrometers to yield stress, small-strain shear modulus and different measures of undrained shear strength are also provided.