Comparison of geogrid and geotextile reinforced earth slabs

Abstract

Presented herein is a comparison of the results of laboratory model tests used to study the bearing capacity of geogrid and geotextile reinforced earth slabs. The parameters studied were the coefficient of friction between the geotextile and the soil, pull-out resistance between the geogrid and the soil, depth below the footing of the first layer of reinforcement, vertical spacing of the layers, number of layers, width size of a square sheet of reinforcement, and tensile strength of the reinforcement. For both geogrids and geotextiles, after an optimum number of layers or width of reinforcement, the bearing capacity did not increase. In addition, the bearing capacity was largest for those geogrid and geotextile reinforced earth slabs where the first layer was closest to the footing and the spacing between the layers was the smallest. Bearing capacity increased directly with increasing reinforcement tensile strength for the geotextile; however, for the geogrid, aperture size and reinforcement tensile strength must be looked at simultaneously. Key words: reinforced earth slab, geogrid, geotextile, bearing capacity, pull-out, friction.