The (GRS-IBS) Geosynthetic Reinforced Soil Integrated Bridge System is a composite bridge structure built using closely spaced layer of geosynthetic reinforcement and compacted granular backfill of GRS abutment that directly supports the bridge and blends the abutment. GRS-IBS consists of three main components: the reinforced soil foundation (RSF), the abutment, and the integrated approach. Foundation systems are complex interactive systems due to the variable material properties of different constituents of the system. The behavior of geosynthetic reinforced soil (GRS) walls always constructed on a rigid foundation has been extensively investigated numerically, experimentally in the past. The foundation soil of GRS wall must have sufficient bearing capacity to prevent failure and excessive deformation. Based on a review of the literature, there is a need to quantify the effect of foundation stiffness on deformations of geosynthetic reinforced soil integrated bridge system (GRS-IBS). This thesis is carried out the effect of foundation system stiffness, vertical reinforcement spacing, and different bridge loading conditions on the performance of GRS-IBS wall using numerical analysis limit to static condition. The numerical model was developed using two-dimensional finite element program of Abaqus version 6.13 software package together with the Mohr-coulomb elastoplastic constitutive model for soils and elastic model for concrete and reinforcement materials. A parametric study using this model was performed by varying influence of design factors such as: the variation of foundation stiffness, vertical reinforcement spacing, and bridge loading. The result of analysis was indicated that horizontal and vertical abutment facing deformation computed by the numerical analysis increased with the wall height in all the simulated models until reaching the maximum value, and then decreased with increasing elevation towards the top of the wall for all model. The lateral and vertical abutment facing deformation computed by numerical analysis in the parametric study increased with the increase in the vertical reinforcement spacing, bridge load, and the decrease in the foundation system stiffness.