Performance Evaluation of Flexible Pavement Using the Finite Element Method

In the design of flexible pavements, tensile strain, compressive strains and its effect on rutting and fatigue are critical parameters. The developed computer program after validation with reported case histories is used to calculate the horizontal tensile strain at the bottom of the bituminous layer (BL) and the vertical compressive strain at the top of the subgrade. These computed strains are incorporated in the fatigue and rutting criteria recommended in Indian Road Congress (IRC: 37-2012) to estimate the pavement life for various hypothetical conditions. Tensile strain at the bottom of BL and compressive strain on top of the subgrade decreases with an increase in the thickness of BL, which results in increase of fatigue and rutting lives. An increase in thickness of the base layer and the increase in its elastic modulus reduces the damage due to rutting, while it has less effect on damage due to fatigue. Such type of analysis proves beneficial for designing a pavement, keeping equilibrium between fatigue and rutting lives. In this paper, using a two dimensional axisymmetric finite element model, above mentioned critical parameters is examined by varying the thickness and material properties of different layers in flexible pavement.