Transportation Research Record No. 1448, Strength and Deformation Characteristics of Pavement Sections

Assumption of a linear elastic system under static loading is questionable for structural response analysis of pavement-subgrade systems under dynamic nondestructive testing and moving wheel loads, especially if a deteriorated pavement is under study. Presented are the results of a parametric study using the three-dimensional finite element ABAQUS code; it investigates the effects of pavement discontinuities and dynamic analysis on the surface deflection response of a pavement-subgrade model under a standard falling-weight deflectometer (FWD) load. An optimum three-dimensional pavement subgrade model of a 18.3-m (60-ft) pavement length was established with a fixed boundary at the bottom and roller supports on the sides. ABAQUS static deflections are in good agreement with the static deflections calculated from the traditional elastic layer analysis for an uncracked pavement. The ABAQUS dynamic response using the backcalculated nonlinear moduli compares reasonably with the measured FWD deflections on an asphalt pavement site. The ABAQUS special-purpose gap elements are used to simulate longitudinal and transverse cracks in the surface layer. Dynamic deflections are 17 percent higher for a pavement with longitudinal cracks as compared with an uncracked pavement.