Meissa Fall

Nonlinear Mechanical Behavior Analysis of Flexible Lateritic Pavements of Senegal (West Africa) by FEM for M.-E. Pavement Design

Pavement design in Senegal is based on a linear elastic behavior of pavement materials and the hypothesis of a static loading. However, previous works on the mechanical behavior of road materials showed that this one is reversible after several loading cycles and depends on the applied stress. The described behavior is from then on, purely nonlinear. One of the objectives of this research is to determine the parameters of response of lateritic pavement materials submitted to road traffic by using FEM. Therefore, experiments were made on gravel lateritic soils from Dougar, Sébikotane, Mont-Rolland, Pâ Lo and Ngoundiane. The Young’s modulus of the materials was defined in unconfined compression test while repeated load triaxial test was performed to determine the resilient modulus of the gravels and the appropriate model (Uzan model). An implementation was realized with Cast3M©. The importance of the nonlinearity was revealed in a very clear way and was crucial in the construction of the calculation algorithm. The observations for certain conditions showed that the values of the critical responses are more important for the linear model than for the nonlinear model. However, this trend should be validated by further studies.