STUDY OF PAVEMENT RESPONSE TO VEHICLE LOADING AND EVALUATION OF DAMAGE DUE TO OVERLOAD

Abstract

Flexible pavements are extensively utilized in roadway and airport construction due to their capacity to endure traffic loads and deformations. Finite element (FE) analysis has emerged as a prominent tool for projecting the performance of flexible pavements subjected to varying traffic loads and environmental conditions. In this report, an FE model of a flexible pavement was established and scrutinized through the use of the commercial software ABAQUS. The model encompassed numerous layers, including asphalt concrete, base, subbase, and subgrade layers. Validation of the FE model was done using IITPAVE. The linear model of the developed stress exhibited an increment in response with a rise in vehicular speed, whereas the viscoelastic model revealed a decline in stress with an increase in vehicular speed. It was found that the viscoelastic pavement has a higher response than linear elastic pavement and was concluded that the viscoelastic pavement is subjected to damage earlier than the linearly elastic pavement due to the development of more strain in viscoelastic pavement than in linearly elastic pavement. The findings of the FE analysis divulged that the pavement responses were heavily influenced by the individual properties of the various pavement layers and the traffic loads applied. Additionally, the report addresses the issue of pavement failure due to overloaded vehicles on highways in Nepal, which reduces the road's service life. The findings indicate that the major cause of pavement failure is vehicle overload, with a decrease in remaining service life for the pavement ranging from 46 to 68 percent for an average value of overloading. The study also found that the required increase in asphalt overlaying due to vehicle overload is 15 to 21 percent for an average value of overloading. The CESAL values obtained through different methods provide fairly consistent estimates for the reduction in pavement service life and the increase in overlay thickness.