Dynamic Shakedown Analysis of Flexible Pavement under Traffic Moving Loading

Abstract

Shakedown theory is often used to analyze the plastic behaviors of structures subjected to variable complex loads. It is an effective way to predict the maximum load under which the failure due to plastic collapse or excessive permanent deformation of pavement will not occur. Based on Melan's lower-bound shakedown theory, this work has proposed a numerical method for estimating the shakedown limit involving the effect of traffic moving speed. The dynamic response of elastic stress to traffic moving speed is computed using combined Finite Element-Infinite Element (FE-IE) method. The shakedown limits for a two-layered pavement system have been investigated at various traffic moving speeds. It shows that the shakedown limit early reduces and subsequently turns to grow as the moving speed increases. The shakedown limit decreases to the minimum when the traffic speed reaches the Rayleigh wave speed of subsoil. In order to provide an optimized design of the pavement system, the dependence of shakedown limits on the material properties of pavement system has also been estimated. Eventually, the characteristic distribution of critical residual stress is discussed.