The influence of soil type on interface behavior under pullout conditions

The rapid increasing application of geosynthetics as reinforcement elements for earth structures requires a careful examination of soil-reinforcement interaction mechanisms. The soil-geosynthetic interaction can be complex because it is affected by structural, geometrical, and mechanical characteristics of the geosynthetic, as well as by boundaries and loading conditions and the mechanical properties of soil. All pullout tests were performed at constant rate of displacement equal to 1.0 mm/min, until geogrid tensile rupture or until a total horizontal displacement of 100mm was achieved. The influence of the type of soil can be showed comparing the pullout curves that refer to the tests carried out at the same test condition embedded in two different granular soils. A marked increase in soil-geogrid interface pullout resistance was observed when the soil contained a significant percentage of particles with size similar to the thickness size of the geogrid-bearing members, but smaller than the geogrid openings