The Micromechanical Behaviour of a Biogenic Carbonate Sand

An experimental investigation of the micromechanical behaviour of a biogenic carbonate sand from the Philippines was conducted. Mechanical parameters of sands at the micro-scale are required in order to simulate the particle interactions in numerical analyses carried out using the Discrete Element Method (DEM). The tests were performed on particles obtained from the sedimentation of coral fragments and they were carried out by means of a custom-made inter-particle loading apparatus that enabled the investigation of both the normal and tangential loading behaviour at the particle contacts. The normal loading tests showed a reversible behaviour after the first loading, while the tangential loading behaviour of this sand appears to be dependent on the vertical confinement and mainly reversible for small displacement cycles. Also, the inter-particle friction coefficients at larger displacements are substantially higher than those calculated for other sands using the same experimental procedures.