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

Finite element method in pavement analysis is a type of mechanistic analysis that has widelybeen used by road and transportation engineers these days. this method is used with related programssuch as abaqus/cae which is one of the powerful software on this task. modeling inthis 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 layeredpavement 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 modeledin abaqus/cae. these axles are moving with different velocities. since the model is a flexiblepavement, two important structural damages are “fatigue cracking” and “rutting”. in order tocalculate the allowable number of load repetition to prevent each of those distresses, the horizontaltensile strain under the hot mixed asphalt (hma) layer and vertical compressive strain on top ofthe 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 loadingwith 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 betweentwo configurations of axles and their speed two conclusions have been made. stresses reduce withincrease 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 tandemconfiguration.