Riyam Saleem Abbas Al_ghalibi

The research is performed to study the behavior of a horizontal anchor plate embedded into sandy soil with a high gypsum content as a block or powder in Al-Najaf City/Iraq. In Al-Najaf city, during the works of the different sites’ investigation, it can be observed that a network of interconnect cavities was found at different depths beneath the surface of the soil. These cavities formed due to the groundwater movement towards the Al-Najaf Sea which leads to the dissolution of gypsum and creates cavities in the soil. The suggested technic to treat these problematic soils, as to use a geogrid type of Tanser SS2 as a reinforcement material to increase the shearing resistance and reduce the settlement of the soil. Nineteen model tests were conducted in a laboratory to explain the behavior of anchor plates embedded into the soil at a depth 30 cm below ground surface level with different cavity diameters, cavity locations, plate diameters, and geogrid depths by using a steel box. The experimental program is divided into two major series of tests depending upon the cavity locations (x=0 and 7.5 cm and y=17.5 and 22.5 cm), cavity diameter (d= 15 cm), anchor plate diameter (D=10, 15 and 20 cm), anchor depth (H=30 cm), geogrid depth (h=30 cm) and geogrid width (B=50 cm). The results are presented as a relationship between the applied pullout load and the corresponding displacement, also, the shapes of the wedge failure of each model were measured. The results were referred to the using geogrid enhanced the pullout capacity of sandy soil, especially when the geogrid located directly above the anchor plate (h/H=1) for cases with and without cavity. For no cavity case, the geogrid is very effective in increasing the anchor plate capacity at a small anchor plate diameter (D/B=0.2) with (Tf =195.2%), while a high treated factor due to geogrid can be observed at a medium anchor plate diameter (D/B=0.3) with (Tf =340 %) for cavity cases.