Determination of Pullout Strength of Geogrid in Sandy Soil

Geogrid reinforcement of soil has been successfully used for many years in a wide variety of applications. This paper presents data obtained from a series of laboratory tests performed on the geogrid. The tests were conducted to determine the mechanical property including the tensile strength of the geogrid and its corresponding pullout test. Tests were performed to find out the effect of width of geogrid on the pullout resistance. It was found that the pull-out resistance of geogrid is a function of the relative density of the soil, the length and the width of geogrid specimen. A mechanism of soil-geogrid interaction is described and used to explain the results of' the pull-out tests. A significant finding is that the selection of geogrid specimen dimensions for laboratory pullout tests must take into account the strain to failure of the soil and the stiffness of the geogrid in order to properly represent the maximum pull-out stress that will be available in field applications.