Analysis of the lateral confinement to pavement systems

This study investigates the concept of lateral confinement and the role of shoulder’s confinement to pavement systems. Therefore, plate load tests were conducted on a sandy soil in a model tank where a vertical diaphragm is introduced to simulate confinement. Results revealed lower values of surface deflection, higher values of the elastic modulus and modulus of subgrade reaction with the use of diaphragm close to the point of load application. A relationship was correlated between the elastic modulus and lateral pressure through triaxial tests for aggregate materials. Finite Element Method (FEM) was used for characterization of a two layer pavement system with shoulder of different materials. Plain concrete, asphalt, aggregate and sand were assumed as shoulder’s materials where their lateral supports were quantified and found to be 0.41, 0.33, 0.21 and 0.12 MPa respectively. Moreover, a parametric study was conducted to check role of lateral confinement in the load carrying capacity of a pavement system. It is revealed that providing of a vertical diaphragm under the pavement edge can significantly reduce the pavement thickness, surface deflections and amount of stresses transmitted to the subgrade.