Most of the loads are transferring from the embankment to the subsoil, while seismic load moving from the subsoil base to the embankment and causes nonlinear loads interaction. From the loads characteristics concept, the loads interaction process needs to consider for the loadings sustainability of the subsoil and embankment, which is a criterion from an engineering design point of the view. In this regard, using a suitable economic technique for improving the subsoil of the embankment is essential in geotechnical earthquake engineering. In the present study, to identify the best location of the subsoil that needs to be improved, an investigation was made to achieve the best results of the embankment-subsoil seismic stability design and to estimate embankment-subsoil nonlinear deformation and displacement. The nonlinear finite element method (NFEM) used for numerical simulation performed to realize the best location of the geogrid has to be installed in the subsoil. In addition, the statistical model was developed to identify the acceptability of the best-proposed location of the geogrid installation in the subsoil. The concept of the soil-geogrid interactions in each part of the subsoil is following a different pattern, and this soil-geogrid interaction governs the model seismic resistance. The novelty of the soil-geogrid interaction concept helps to reach safe and economic subsoil-embankment earthquake design. In the future, introducing the geogrid model needs more investigation to reach the best economical model related to the availability of the material in the construction site.