The orientation of biaxial geogrid components affects the bearing capacity and deformation response of bridge strip footings during subgrade reinforcement for bridge construction. In this study, plate load testing was conducted on a strip footing embedded in a clean sand bed reinforced with a single layer of geogrid at a constant depth of 0.25 times the footing width. To evaluate the contribution of each geogrid component, five configurations were considered: unreinforced soil, full biaxial geogrid, perimeter frame without internal ribs, longitudinal rib arrangement, and transverse rib arrangement. The system performance was then assessed based on ultimate bearing capacity, settlement reduction under working stress, initial stiffness, zone of influence of the geogrid, and stored strain energy. The results indicate that the geometric configuration of the geogrid plays a decisive role in the mechanical response of the soil–footing system. The full biaxial geogrid exhibited the best overall performance across all evaluated parameters, achieving approximately 125% improvement in bearing capacity, 40% reduction in settlement under working stress, and 95% increase in initial stiffness compared to the unreinforced condition. This configuration also provided the largest zone of influence and the highest stored strain energy, indicating more effective mobilization of tensile resistance and stress transfer within the soil mass. Maximum reinforcement effectiveness is achieved when the geogrid continuity and rib orientation facilitate the simultaneous confinement of load transfer mechanisms, tensile resistance, stress redistribution, and deformation control.