DESIGN OF FLEXIBLE PAVEMENT INCORPORATING LATERAL CONFINEMENT PARAMETER

This paper reports a study, aiming to identify the structural responses of flexible pavements under wheel loads, to develop a suitable design methodology incorporating lateral confinement mobilised between the pavement edges. In the experimental part of the study, the variation in elastic modulus of subgrade soil under different lateral confinement conditions was investigated. In the analytical part, an attempt was made to study the variation in stresses and deflections in two-layered pavement systems, due to wheel loads occupying different positions from unconfined and confined pavement edges. A proposed methodology for flexible pavement design is presented, using surface deflection as the design parameter and lateral confinement as one of the additional variables. Burmeister's approach was adopted as a guiding tool to develop the methodology, and an economic analysis was also performed. A finite prism model was used to obtain the analytical solutions of different thicknesses and load positions. It was found that vertical deflection at the surface under the centre of the wheel load was considerably reduced, due to introduction of a vertical diaphragm at the pavement. Examples are given of the resulting reductions in pavement thicknesses and construction costs. The paper's methodology can be extended to multi-layer pavement systems.