ASSESSING THE INFLUENCE OF OVERWEIGHT AXLES ON RUTTING LIVES IN FLEXIBLE PAVEMENTS USING PARAMETRIC SURVIVAL ANALYSIS

The existence of rutting or permanent deformation on flexible pavement layers has always been a concern that negatively affects the performance of roads by reducing the lifespan of pavement structure and by posing a safety risk for vehicles over the road. Traffic overloading is one of the primary factors that accelerates the deterioration of flexible pavement. This study aims to determine the time to failure of the flexible pavement structures associated with rutting, to indicate the most significant factors affecting rutting, and to assess the influence of overweight axles on pavement rutting life using parametric survival analysis. The data used in this study are extracted from the LTPP program. The outcomes provide researchers and agencies with a good knowledge of the relations between several predictors including overweight axles and pavement performance and hence increase the ability of pavement to continue functioning properly over the design lifetime. The results indicated the factors that have a significant effect on pavement rutting life. Also, the results revealed that a 1% increase in the percentage of overweight axles can be related to a 16.24% increase in the hazard rate of rutting failure. Moreover, the survival time of rutting life can be reduced by up to 63% with the increase of the percentage of overloaded axles from 0% to 20%.