Effects of geogrid properties on pullout resistance

Study on the pullout resistance was made on the model geogrids. The first sense, special attention was directed to see the effects of the shape of geogrids. All the model geogrids had the same horizontal surface area, but the dimensions of longitudinal and transverse elements were changed to investigate the effects of two vertical areas, i.e. longitudinal and transverse vertical areas, on the pullout resistance were investigated. It turned out that the geogrids of the same horizontal area, stiffness and thickness had the same friction angle between soil and geogrid, but apparent cohesion, displacement and strain distribution were different. The effects of stiffness of the geogrid were investigated in the second sense. Three model geogrids had the same shape and surface friction, but the stiffness was different. The peak pullout resistance of the stiff geogrid was obtained at the small pullout displacement. Difference in stiffness especially affected at the beginning of the pullout test.