Coral sand is widely used in island and reef reclamation projects

but its distinct physical and mechanical properties compared to land-based sand. To explore the deformation mechanism of hydraulic filled coral sand foundation

oedometer tests were conducted on coral sand

considering the combined effects of factors such as gradation

porosity

and loading methods. The initial particle size distribution of coral sand significantly impacts its compression deformation characteristics

with noticeable particle breakage. A larger initial void ratio in gravel sand results in greater compressibility. The deformation of coral sand primarily involves pore filling by particle movement

accompanied by minor particle breakage

all of which are irreversible plastic deformations. Consequently

the unloading index of coral sand is only 1/10 that of clay. Finally

a three-dimensional model of the aviation oil storage tank was created using Plaxis 3D software. Using mechanical parameters obtained from laboratory experiments

the deformation of the coral sand foundation in aviation oil storage tank engineering under cyclic loading and unloading was studied. The model’s accuracy was validated by comparing it with the monitoring results of the aviation fuel storage tank project at Maldives’ Ibrahim Nasir International Airport. At the maximum storage capacity of the aviation oil storage tank

the coral sand foundation reaches its peak deformation. At this load level

multiple loading and unloading cycles will not cause further deformation

providing valuable guidance for engineering safety control.