Soil nail walls’ application includes retaining structure construction and maintenance, road expansion beneath existing bridge ends, highway cut excavations, and both temporary and permanent excavations in urban settings. In order to address unstable natural or manmade soil slopes, soil nailing is a restorative treatment that stabilizes the soil. This study investigates the effectiveness of soil nailing for stabilizing deep excavations under seismic loading using a parametric approach. A laboratory soil nail model was constructed to examine the influence of nail spacing, inclination, and length on excavation behaviour. A finite element model in Plaxis 2D was developed to replicate the experimental setup. The results indicate that wider nail spacing (10 cm) led to slightly higher horizontal (0.016–0.02 mm) and vertical (0.01 mm) displacements compared to closer spacing 5 cm suggesting reduced stability. Nail inclination (15°) offered some improvement, with marginally lower displacements (0.016–0.018 mm) and higher factor of safety values compared to no inclination. These findings highlight the importance of nail spacing and inclination in optimizing soil nail design for deep excavations. This research aims to provide valuable insights for engineers designing deep excavations with soil nail reinforcement. Furthermore, the research will be complemented by future experimental work to validate the numerical models.