Influence of Geosynthetic Reinforcement on Shear Strength Characteristics of Two-Layer Subgrade

Due to low bearing capacity of soft clayey soils, in places that because of economic, military or geological conditions, we are oblige to build a structure on such soils, geosynthetic will be used to reinforce the soil and improve the bearing capacity. Particularly, in roads, geosynthetic is placed between the interface of granular materials and soft-soil sub grade to improve the bearing capacity of composite layers. In past researches, the behavior of one layer soils which had been reinforced with different kind of geosynthetic, were studied by experimental and analytical methods and some numerical models have been developed. In this paper the behavior of two layers soils (granular base-clayey sub grade) that have been reinforced with some kind of geosynthetics is investigated. Large scale direct shear tests are performed on reinforced and unreinforced samples with different geosynthetics. The obtained results show that the inclusion of geosynthetics materials improves the shear strength of two layered soils. It implies that the geosynthetic-reinforced soils in sub base layer of roads will perform better than non-reinforced ones and therefore, the load carrying capacity of basement is improved.

کلیدواژه ها:

Shear Strength ، Geosynthetic ، Large scale direct shear test ، clay ، subgrade