Shell foundation is an alternative for the flat counterparts with proven records to increase bearing capacity and reduce settlement. Furthermore, due to its geometrical configuration it provide high resistance to earthquakes and lateral loads. The objective of this study is to present the results of numerical investigation performed on shell foundations. Finite-element analysis using PLAXIS software was employed to examine the parameters govern the geotechnical behavior of soil-shell-structure interaction. Parametric analysis was performed to examine; the shell geometry and thickness in granular soil for both upright shells and their inverted counterpart. Load carrying capacity and the in-situ stresses in the surrounding soils are investigated at working load and ultimate loading states. In this study, linearly–elastic behavior of concrete material is assumed while soil media is modeled under nonlinear elastic perfectly–plastic conditions following the Mohr–Coulomb yield criterion for the sand. The failure mechanism was deduced and comparative analysis was performed for different shell foundation models and the flat counterparts are presented. Shell models compared to flat counterparts showed improved load–settlement characteristics for the same soil conditions. For similar planar surface area, breadth of footing and footing angle for same soil conditions, the inverted shell footings offered better load–carrying capacity as compared to the upright shells. From the parametric study, for same planar sectional area of footing and same soil conditions, the load–carrying capacity was found to increase with both increasing shell thickness (ts) and increasing shell angle (θ). The results demonstrates that shell angle is the over–riding parameter over shell slab thickness however the shell thickness parameter itself should not be underestimated and carefully considered in design.