Mechanical property and deformation behavior of geogrid reinforced calcareous sand

The strength and deformation properties of maritime geotechnical structures made primarily of calcareous sand are critical for project safety, and geogrid reinforcement is a promising new approach. A series of consolidated drained triaxial experiments were conducted to evaluate the mechanical property and deformation behaviors of geogrid reinforced calcareous sand (GRCS), taking into consideration the impacts of the geogrid layer, relative density, particle size, and confining pressure. In comparison to the unreinforced calcareous sand, the strength of the GRCS is greatly enhanced, and the deviatoric stress-strain curves are altered from slightly softening to hardening, as well as the suppressed shearing dilatancy. The geogrid, relative compactness, particle size, and confining pressure are all intimately related to the volume changes and shearing dilatancy of reinforced specimens, but particle crushing is mostly impacted by the confining pressure. The interactions of geogrid ribs and calcareous sand particles are summarized as two types of constraint and friction using scanning electron microscope tests to establish a simplified calculation method of horizontal and vertical equivalent additional stresses that could provide a reference for revealing the mechanical mechanism of GRCS. •Geogrid reinforcement significantly improve the strength of calcareous sand.•Multiple effects on geogrid reinforced calcareous sand are considered.•Volumetric strain and particle crushing characteristics are fully evaluated.•Micromechanical mechanisms of geogrid reinforced calcareous sand are revealed.