A Numerical Study on the Effect of Geocell Reinforced Base Layer on the Fatigue and Rutting Life of Flexible Pavements using Nonlinear Finite Element

In the past few years, with the advances made in the production of geosynthetic products, the use of these products in the pavement reinforcement has increased dramatically. Among the geosynthetic products, geocell improves the performance of the pavement due to the proper 3D confining of aggregates materials inside its cells. In order to investigate the effect of base layer reinforced with the geocell, six different geometries with reinforced and unreinforced base layer were simulated in ABAQUS finite element software. The behaviour of aggregate base and subbase layers were consirdered nonlinear which is implemented in ABAQUS by a FORTRAN subroutine. In the next stage, the results of the ABAQUS program as well as FORTRAN subroutine were validated using the results of KENLAYER and MICHPAVE programs as well as a full scale test. The results showed that the results of the ABAQUS program are consistent with results of other programs and also with the results of the fieled test. According to this research, by reinforcement of base layer using geocell, the surface deflection responses decreases betwen 5 to 10.28%, the tensile strain responses at the bottom of the asphalt decreases between 7.15 to 12.24% and the vertical compression strain on the top of subgrade decreases between 5.1to 9.19%. Also, the damage analysis was conducted based on the Asphalt Institute relations and results showed that the reinforcement of base layer increase asphalt fatigue life by 21.68-34.94% and subgrade rutting life by 20.89-35%.