Review on dynamic response of road pavements to moving vehicle loads; part 2: Flexible pavements

This second part of the review paper on the dynamic response of road pavements under moving vehicle loads deals with flexible pavements. Flexible pavements are composed of an asphalt concrete layer supported by various granular foundation layers. This system of layers can be simulated mainly by a homogeneous or nonhomogeneous (continuously or discretely) half-plane or half-space with isotropic or anisotropic, elastic, viscoelastic, poroelastic, elastoplastic or viscoplastic material constitution in the layers. The vehicles are simulated by concentrated or distributed loads, which may be time dependent, travel with constant speed or exhibit acceleration/deceleration. The equations of motion of these pavements for their response determination to vehicle loads are solved by analytical/numerical or purely numerical methods, like the finite element or boundary element method, operating in the time or frequency domain. Accuracy and efficiency of the various methods of solution are discussed. Response results coming from these methods are compared with those coming from field experiments. Some special effects on pavement response, such as surface irregularities, acceleration/ deceleration or layer interface contact conditions are also discussed. The paper closes with a list of conclusions and recommendations for future research in areas of importance.