The Department of Highways (DOHs), Thailand, designed and constructed a 6m high reinforced earth embankment near Highway No.11 Phitsanulok-Uttaradit in Thailand. Two types of reinforced earth embank-ment were constructed; on one side, bags of soil were used to construct a Reinforced Steep Slope (RSS) with a 70 degree sloping face and on the other side, a Mechanically Stabilized Earth Wall (MSEW) was constructed with a vertical concrete panel as a facing. The test embankment was 18m long and 15m wide at the top. Three types of polymeric geogrid reinforcements were installed in the reinforced steep slope (RSS) facing and two types of metal-lic reinforcement were installed in the mechanically stabilised earth wall (MSEW) facing. The polymeric geogrid reinforcement consisted of polyester (PET), high density polyethylene (HDPE) and polypropylene (PP), while the metallic reinforcement consisted of steel wire grid (SWG) and metallic strip (MS). Monitoring instruments such as inclinometers, settlement plates, total pressure cells, standpipe piezometers, vibrating wire strain gauges and fibre optic strain gauges were installed to check the displacement, stresses, excess pore water pressures, groundwater ta-ble, and strains in the reinforcing material. PLAXIS 3D (Version 2011) was utilised for the FEM numerical simula-tions of the embankment. The behaviour of a reinforced soil slope (RSS) and mechanically stabilised earth wall (MSEW) on a hard foundation were observed and compared with the predictions from PLAXIS 3D software, in terms of any lateral and vertical deformation.