Numerical Comparison of Pavement Distress Due to MovingLoad under Dual-wheel Tandem and Tridem Axles

Finite element method in pavement analysis is a type of mechanistic analysis that has widely been used by road and transportation engineers these days. This method is used with related programs such as ABAQUS/CAE which is one of the powerful software on this task. Modeling in this software has been developed from 2D static models to 3D dynamic models which are closerto reality due to the more precise definition of material properties. A 3D model of a three layered pavement system has been studied in this paper. Viscoelastic behavior definition for asphalt concrete (AC) layer which is loaded by Dual-wheel Tandem and Tridem axles has been modeled in ABAQUS/CAE. These axles are moving with different velocities. Since the model is a flexible pavement, two important structural damages are Fatigue Cracking and Rutting . In order to calculate the allowable number of load repetition to prevent each of those distresses, the horizontal tensile strain under the hot mixed asphalt (HMA) layer and vertical compressive strain on top of the subgarde are needed. The concentration of this study is based on the responses of flexible pavement. Moreover, a comparison due to moving Dual-wheel Tandem and Tridem axles loading with different velocities is made. The parameters used for comparison are the allowable numbersof load repetition to prevent Fatigue Cracking and Rutting . Due to the comparison between two configurations of axles and their speed two conclusions have been made. Stresses reduce with increase in speed up to 100km/h under two axle configurations. Also, the allowable number ofTridem axle passages to prevent Fatigue Cracking and Rutting is higher under Dual-wheel Tandem configuration.