Simulation of shakedown behavior for flexible pavement's unbound granular layer

Full-depth asphalt concrete pavements are generally designed to control fatigue cracking and reduce potential rutting when subjected to repeated heavy traffic loads. A particular interesting question is whether a limit load exists below which excitation shakedown in the sense that the granular layer does not accumulate further deformation. Although pavement design guides give more weight to asphalt concrete layer failures, granular failure may not be ignored; especially for thin layers and/or heavy load. The behavior of granular layers used in base and, sub-base layers of flexible pavement is complicated due to its nonlinear elastoplastic response when subjected to dynamic traffic loading. The objective of this paper is to present a new simplified simulation model for the Shakedown behavior of granular layer in flexible pavement. This method is integrated with Mohr-Coulomb criterion, which is used and applied to simulate the response of unbound granular layers to dynamic loading in a numerical analysis. The results of analysis are then compared to simplify the results of modeling without considering shakedown effects and then, the conclusions are drawn.