Three–Dimensional Finite Element Analysis of Doweled Joints for Airport Pavements

This paper investigates various aspects of the structural behavior of doweled joints, including load transfer, in rigid airport pavement systems using nonlinear three–dimensional finite element methods. The finite element models include two concrete slab segments with dowels connecting them. The concrete slab and supporting layers are simulated by continuum solid elements to enhance the accuracy of the simulation. Solid elements can capture the severe deformation gradients in the concrete slab in the vicinity of wheel loads, allow the modeling of non linear behavior in the supporting layers and the modeling of frictional contact interfaces between the concrete slab and supporting layers. These features have not been considered in classical approaches. The structural behavior of the doweled joint is investigated for various design and loading conditions, including: (1) tire pressure, (2) dowel spacing, (3) slab thickness, (4) dowel looseness and (5) multiple wheel loads. The amount of load transfer can be obtained directly from the shear force in the Timoshenko beam elements that simulate dowel. According to the finite element results, 15 to 30% of the applied wheel load is transferred to the adjacent slab segment by the dowels. This number varies in accord with design and loading conditions. In addition, 95% of the transferred shear force is carried only by the nine or eleven dowels which are closest to the applied load.