Evaluating the Performance of Rehabilitated Roadway Base with Geogrid Reinforcement in the Presence of Soil-Geogrid-Interaction

One of the efficient techniques to improve the behavior of the paved road under traffic loads is implementing the geosynthetic material in the sub-base or the soil under the road. In the past years, many researches have been done about this topic, but the study on the effect of soil/load conditions on the performance of the rehabilitated paved road by geogrid in order to investigate the effective parameters on it is still open. In this paper a series of 2D FEM models using the software PLAXIS-2D are carried out to evaluate the effects of soil/load conditions which includes the effect of the subgrade material and load properties (such as modulus of elasticity, Poisson s ratio, drainage conditions, shear strength and the area of load), in the presence of soil-geogrid-interaction. The results showed that the use of a geogrid reinforcement layer decreases the vertical settlement in a soft subgrade surface, and this indicates that the main mechanism of the geogrid is to restrain soils from lateral displacement through interlocking with the particles. In addition, it is concluded that increasing the Poisson s ratio of the subgrade leads to reducing the vertical settlement and increasing the value of modulus elasticity leads to decrease of the vertical displacement, it is also shown that with increasing un-drained shear strength, vertical deflection has also decreased.