DETERMINATION OF OPTIMUM TENSILE STRENGTH OF GEOGRID REINFORCED EMBANKMENT

Soil-reinforcement interaction is a key issue in the design of geogrid-reinforced soil structures. Therefore, it is important to analyze the interaction mechanism between the soil and geogrid reinforcement. A multi-layered geogrid-reinforced embankment with steep slope was proposed for this study. This embankment was reinforced by five layers of biaxial geogrids. According to the stability of reinforced earth structures and the mechanical interaction between geogrid and soil analysis, the optimum tensile strength of geogrid for each of layers was determined. This must consider the factor of safety, soil-geogrid interface shear stress and the horizontal and vertical displacements of soil and the mobilized geogrid. Consequently, a series of soil-geogrid interaction numerical models were developed to simulate the reinforcing systems. Simulation was performed using finite difference-based software FLAC version 4.00 (Itasca, 2000). Since the displacements of soil and geogrid reinforcement are relatively small in this study, the determination of optimum tensile strength of geogrid was strongly influenced by factor of safety and soil-geogrid interface shear stress.