The site investigation was focused on quality assessment of initially built artificial medium-sized embankment slope as a case study. The embankment had high initial water content more than two times the optimum water content obtained by moisture-density standard compaction curve. To understand the behavior three different slopes were recreated using bucket of excavator through increasing compaction by tamping method. Furthermore, smooth roller was used to pass on the top of the embankment and divided into zoned into three zones based on increasing the number of passes. Analyses confirmed that however dry densities increased with increasing compaction, stiffness reduced at the highest water content around the embankment. Then a triangulation model is proposed to check the effect of stiffness at variable water content at the same degree of compaction. This model can able to explain the role of water content to increase/decrease in stiffness of the ground.