Profiling in-situ stresses in clays using penetrometer test results

In this paper, a penetrometer-based methodology for characterizing in-situ stresses in clays is proposed. For this purpose, a correlation model between the effective stress and the penetration resistance is established. Piezocone and T-bar penetrometers, both of which are commonly used in practice, are introduced into the proposed method. The proposed correlation model is given as a function of the penetration resistance, penetration resistance factor and strength increase ratio, considering that the penetration resistance and undrained shear strength are both governed by the effective stress. To check the validity of the proposed method, case examples are selected and used to compare measured and predicted in-situ effective stress profiles. It is observed that the predicted stress profiles agree well with the measured profiles for both piezocone penetration test (PCPT) and T-bar test cases. The effect of soil constitution on the effective stress for the proposed method is also examined.