Strength characteristics of loose to medium dense sand deposits improved by sand compaction piles (SCPs) are assessed by performing three-dimensional (3D) finite-element analysis using PLAXIS 3D. The Mohr-Coulomb model is employed to model the behavior of both sand and SCP. A laboratory test is performed on the SCP-treated sand deposit to validate the finite-element (FE) result and they are in good agreement. A parametric study is conducted on field-scale SCP FE models considering variations in the properties of sand deposit and geometrical parameters of the SCP on the pressure-settlement response. Based on the FE results, it is found that a nearly 21% increment in the ultimate bearing capacity of the SCP-treated sand deposit can be obtained when the diameter of the SCP is increased by 100 mm. Settlement improvement factors are estimated for the treated sand deposits at selected bearing pressures to understand the extent of improvement achieved. © 2021 American Society of Civil Engineers.