Modeling of stresses for cracking in pavements
Résumé
Pavement degradations are not directly taken into account in current pavement design methods (de Lurdes Antunes, 2002). They can be modeled using 3D finite element methods, but such calculations can be very time-consuming. To make a proper analysis of crack initiation and propagation in asphalt or concrete pavement structures, we propose to use a simplified plate model linked to the Boussinesq model for the soil (Johnson, 1992). This simplified model is built with a polynomial approximation of stress fields for each layer (Chabot, 1997) (Chabot et Ehrlacher, 1998). It introduces, as variables, stresses defined at each interface and leads to a 2D model. It can be viewed as superposition of Reissner's plates linked together by interface forces. The stress fields obtained are very close to those given by 3D finite elements (Carreira et al., 1998). This approach is very fast and produces regular stress fields near cracks at the interface of two different layers. Equations are solved numerically under Matlab. Results are compared successfully with finite element calculations on 3D pavements and 2D cracked pavements.