Contribution of Geosynthetic Reinforcement to Granular Layer Stiffness

This paper describes the contribution of geosynthetic reinforcement to improved stiffness of a granular layer originally constructed as a working platform but serves as a subbase layer after pavement structure is constructed. Large-scale model experiments were conducted that demonstrate the improved stiffness of granular layers reinforced with 4 types of geosyntetics. The load-elastic deflection data is analyzed by dividing the granular layer into sublayers including a reinforced sublayer with a thickness of 100 mm to isolate the effect of reinforcement on elastic modulus. The comparison of the elastic modulus parameter of this layer to that of the unreinforced sublayers indicate that there is an increase of 1.1 to 3.0 times in the elastic modulus depending on the type of geosynthetic. This improvement is also a function of the overall layer thickness because of the effect of shear strain amplitude that is not accounted for in the elastic modulus model.