The construction of pavements depends on the availability of good quality materials, especially for the construction of the base course and subgrade. The geotechnical properties of poor materials and sand pose many difficulties for the construction of pavement bodies, which must be either corrected to improve their properties or reinforced or eliminated altogether and replaced by expensive noble materials. Consequently, the project would be too expensive. The use of geosynthetics for reinforcement in these layers presents an interesting perspective to this insufficiency. The presented work is situated in the context of the evaluation of the mechanical behavior of flexible pavements reinforced by geosynthetics of alveolar type in which we started in first stage a modeling by software FLAC 2D version 4.The modeling is carried out in two cases reinforced and not reinforced. The second step is to carry out a test bed in-situ and to measure the bearing capacity and the deformations ofthe reinforced soil on site by plate tests. And we finish with a comparative study between the numerical model and the experimental model.