Numerical evaluation of geocell-reinforced flexible pavements under traffic loads

Although several analytical and numerical approaches have been devoted to investigate the shakedown behavior of pavements, shakedown limit of reinforced pavements in particular geocell-reinforced pavements have not been explored yet by load-displacement numerical means. Bahaviour of a typical three layer pavement reinforced with geocell has been investigated under repeated vertical trafic loads by three dimensional finite element elasto-plastic analysis based on shakedown failure and servicability criteria. Three different cases of unreinforced, base layer reinforced and subgrade reinforced pavement were taken into consideratation and subjected to a variety of vehicle loads. Shakedow limit which is is the multiplication of initial load to shakedown coefficient for each pavement under each load was determined through a trial and error process. Results indicate that reinforcement of subgarde by geocell significantly improves the shakedown coefficients of pavements. Reinforcement of base by geocell increases the shakedown coefficient of pavements as well as but not as much as subgrade reinforcement. Results also indicate the sensitivity of shakedown coefficient and shakedown bearing capacity to intensity and shape of the contact area of different loads so that the most extreme case was observed for P=22 ton. Variation of accumulated plastic displacement prior to shakedown state has also been presented and discussed.