The　bearing　capacity　and　deformation　behavior　of　coral　sand　foundations,　a　geotechnical　structure　commonly　employed　in　coastal　and　island　construction,　are　investigated　in　this　study.　Coral　sand　presents　unique　challenges　due　to　its　angularity　and　crushability,　which　affect　interparticle　interactions.　Model　tests　and　three-dimensional　discrete-continuous　coupled　numerical　simulations　are　performed　to　understand　these　complexities,　focusing　on　the　impacts　of　relative　density,　footing　size　and　shape,　and　particle　crushing　on　the　foundation　performance.　The　testing　and　numerical　simulation　data　reveal　that　the　bearing　capacity　of　coral　sand　foundations　significantly　improves　with　increasing　relative　density　and　footing　size.　Compared　with　square　footings,　circular　footings　exhibit　superior　bearing　performance　at　a　70%　relative　density.　However,　increased　particle　crushing　reduces　the　bearing　capacity.　These　findings　are　evaluated　and　compared　with　the　theoretical　ultimate　bearing　capacities.　Intense　crushing　and　occlusions　are　observed　directly　beneath　the　footing,　with　marked　increases　in　particle　fragments,　microscopic　contact　forces,　and　coordination　numbers　within　this　core　region.　Additionally,　the　deformation　analysis　reveals　a　symmetrical　failure　pattern　in　the　coral　sand　foundations.　This　study　delves　into　the　microscopic　interactions　between　particle　crushing　and　its　influence　on　the　bearing　and　settlement　performance,　offering　insights　into　the　interplay　between　crushing,　stress,　and　deformation.　©　2024　Elsevier　Ltd