Publication

Abstract : Carbonate sands are prone to chemomechanical degradation in the form of particle size reduction and change in particle morphology due to their biogenic formation. Such degradation consequently alters strength and stiffness of the sand. Therefore, it is essential to model the mechanical response of carbonate sand accounting for the particle size variation and its impact on the strength parameters. The present study explores a possible avenue based on experimental observations and phenomenological understanding to represent those parameters as the functions of index properties, which are affected by the grain size and shape variation. A set of chemically treated carbonate sand specimens having different grain size distributions was examined; the mechanical responses, especially the strength, stiffness and critical state, were determined via drained triaxial compression tests with different initial packing conditions. The experiments show that variation in the granular packing due to dissolution influences the shear strength. Based on the obtained results, a simple constitutive modelling framework is proposed to capture the shear strength of degraded carbonate sand in reference to the undegraded sand sample while accounting for the initial grain size distributions and packing. Finally, a discussion is presented to augment the model for predicting the coupled chemomechanical deformation response.