A retaining wall system that combines capillary barrier principles and utilization of geobags, Geobarrier System (GBS), has been proposed. The expected performances of the GBS after construction and during rainfall were investigated using numerical simulations. Coupled stress-pore pressure analyses were conducted to obtain the horizontal displacement, surface displacement and tension forces in the geogrids of the GBS. The results showed that the horizontal displacements in the GBS were affected by rainfall infiltration. The GBS restricts water infiltration into the residual soil layer hence minimizing the horizontal displacements and tension forces in the geogrids.