Use of Two-dimensional Finite Element Analysis to Represent Bending Response of Asphalt Pavement Structures

Abstract

Use of the finite element method (FEM) and other advanced analysis techniques is suitable for evaluation of pavement response and performance. Three-dimensional FEM analysis provides most accurate representation of pavements; however, it is costly, particularly for predictions that involve continuously changing structures and thousands of load applications of varying magnitudes and positions. Axisymmetric and two-dimensional analyses provide simpler, more cost-effective solutions at the expense of accuracy. This paper describes a study undertaken to evaluate discrepancies between two- and three-dimensional analysis of asphalt pavements, and to determine whether a modified two-dimensional analysis could be used as a reasonable approximation of three-dimensional bending response. Discrepancies between two- and three-dimensional analyses were found to be dependent upon the pavement structure. An approach was developed to use pavement structural characteristics to define an adjustment factor which could be applied to the loading in the two-dimensional case such that two-dimensional analyses would reasonably estimate the critical tensile pavement stresses as computed from three-dimensional analyses. The benefits and limitations of the approach are discussed, and an example of its use in evaluating crack growth is illustrated.