This study expects to demonstrate that a) basal deformation and roughness have influence on stress distribution within embankments and b) implementing of Bézier Extraction in IsoGeometric Analysis (IGA) substantially improves the numerical robustness. Two-dimensional elastic solutions of embankment to which the prescribed basal deformation of either subsidence or uplift and different condition of either fully rough or fully smooth base has given were compared and discussed, focusing on the variation of pressure profiles. The numerical results obtained from IGA were validated with those of finite element method (FEM), revealing that the performance of IGA under Bézier extraction is superior to FEM by achieving the lower computational resources necessary to obtain the same accuracy.