Dilatancy behaviors of calcareous sand considering particle breakage

Calcareous sand is the main geomaterial available for island-reef reclamation construction projects in the South China Sea. To clarify the effect of particle breakage on the dilatancy of calcareous sand, multiple consolidated-drained triaxial shear tests were conducted on calcareous gravelly sand (CGS) under different conditions. On this basis, dilatancy assessment indices were constructed from the perspectives of stress ratio and dilatancy ratio, and their relationships with the initial physical parameter and stress level of CGS were established. Next, the variations in particle breakage of CGS with compactness and stress level were explored, and a physical model was proposed to predict particle breakage according to plastic work. Finally, the relationship between dilatancy and particle breakage was established for CGS. The results lay a research foundation for developing an elastoplastic constitutive model considering the effect of particle breakage for CGS.Graphical abstractIn this study, the dilatancy of calcareous sand was investigated under varying relative densities and effective confining pressures. Then, the variations in the particle breakage of calcareous sand with compactness and stress level were revealed. Finally, the relationship between dilatancy and particle breakage of calcareous sand was established.