Comparative Structural Analysis of Flexible Pavements Using Finite Element Method

Abstract

ABSTRACT The evaluation of bituminous concrete mixes for their tendency to rutting has been an important research field for many years. Rutting is a major type of distress encountered in bituminous pavements. The Finite Element Method (FEM) is a numerical analysis technique to obtain various structural parameters such as stress, strain and deflection of pavement layers. The objective of this paper is to study the sensitivity of these variables in reducing the vertical surface deflections, the critical tensile strains at the bottom of the bitumen layer and the critical compressive strains on the top of subgrade using the finite element method. This study has been carried out in order to compare the performance of flexible pavement using the finite element method and KENLAYER. Vertical surface deflections in flexible pavements have always been a major concern and are used as a criterion for pavement design. It is desirable to reduce the deflections as much as possible. This paper deals with ways to reduce deflections by varying the design configuration, such as increasing the Hot Mix Asphalt (HMA) modulus, the base modulus, sub base modulus and the subgrade modulus. Another objective of the present study is to investigate the effectiveness of two different methods in reducing vertical surface deflections (w o ) and the critical tensile strains in the bitumen layer (ε t ) or the radial strains at the bottom layer of HMA. The finite element method was adopted to evaluate the effectiveness of the two methods and the sensitivity of various factors