An experimental study on pullout behaviour of anchors in reinforced clay

Foundation of some structures e.g. jetty structures, transmission towers, mooring systems etc, experience uplift as a consequence of moments due to horizontal forces and wave actions. To resist uplift plate or pile anchors are adopted as foundations of such structures. If the shear strength of surrounding soil is too low to resist uplift, the required shear stress in soil may be mobilised by using reinforcement e.g. geotextiles or geogrids. In the present investigation pullout tests have been done on model square anchors of steel in a brass tank of 380 mm diameter and 500 mm height. Tests were carried out both in reinforced and unreinforced soils. The paper highlights the effect of position of geogrid reinforcements on ultimate uplift capacity and axial movement of anchors at failure and the extent of failure zone at the soil surface as it developed around the anchors.