Having noted the lack of adequate documentation on road earthworks, linked to the lack of national standards in Senegal that define the conditions of realization, the object of this document is to propose a method for the proper execution of earthworks and the layers form. To this end, a study was conducted on the soils of one of the 14 regions of Senegal, namely the region of Thiès, one of the second cities of the country which is 87 km from the Senegalese capital Dakar. Two roads of 2.5 km long were selected to make manuals sampling of these platform soils in Thiès, the first axis in the municipality of Montrolland located 12 km north of the study area and the second in the rural municipality of Khombole which is 8 km east of the study area.