Effect of roughness on soil-geogrid interaction in direct shear mode

Contact surface roughness and geogrid aperture size are among the factors affecting soil-geogrids interaction. In this study, to investigate the effects of these factors, large-scale direct shear tests have been conducted using a well graded sand at a relative density of 80% reinforced with three geogrids having different aperture size. Samples were subjected to normal pressures of 12.5, 25 and 50kPa and sheared at a rate of 1mm/min. Geogrid surface roughness was achieved by gluing single sized sand particles. Results show that increasing geogrid surface roughness increases shear strength at soil-geogrid interface and there is an optimal relation between geogrid aperture size and shear strength increase

Keywords:

Geogrid , Direct shear , Interaction , Roughness.