Numerical Modeling of Using Ggeosynthetics in Improving the Behavior of Subgrade Soil.

In this research, numerical simulation using the finite element method and PLAXIS numerical software (version 8.2) were used. Also, calculation point of the road settlement, which is the criterion for comparing different models, is selected in the loading center on the road, which is considered as representative of the road settlement in the output results of the vertical displacement. Results of the numerical investigation of the effect of tensile strength of geosynthetics on the road settlement show that this parameter did not have significant effect on the road settlement. Also, from the numerical modeling of the effect of the length of geosynthetics on the road body, it is determined that the vertical settlement in modeling with geogrid of the same size as the width of the road (which is equal to 7 meters in this model) is 3.65 mm and with 9 meters wide geogrid it is equal to 3.5 mm. Results showed that if the amount of friction between geosynthetic element and soil is considered equal to the internal friction angle of the soil, the road settlement at the loading center of the model has decreased by 12%. Finally, investigation of the effect of geosynthetic element placement on the road settlement shows that by moving the geosynthetic layer from the sub-base-substrate boundary to the top-base boundary, the road settlement is decreased by 0.9 mm. [ABSTRACT FROM AUTHOR]