Investigating the circular anchor plate behavior placed in layered soil

Ground anchors are foundation systems that conduct forces from the structure to the ground for preventing overturning moments and pullout forces that can jeopardize the integrity of a structure. Many structures have been studied and built with anchors to stabilize and avoid failure. The effect of the clay layer location and the clay consistency on the behavior of the anchor plate is studied in this research. The soil sample was brought in from the province of Al-Najaf (Iraq). The experimental work was performed in a steel container with dimensions (70 cm x 70 cm x 70 cm). A model of a circular plate of 10 cm diameter was placed at a constant depth of 30 cm from the surface soil. The relative density of sand in the steel container was kept constant at 60%, and the clay was prepared in four different states: solid, semi-solid, plastic, and liquid, with densities of (14.6,14.8,11.6, and 9.8) kN/m3 and water content of (11, 26.5, 46.65, and 62) % accordingly. The uplift capacity value was obtained from the load-displacement curve. The uplift capacity of the soil layers showed a high value of the stabilizing plate when the sandy layer is above the clay layer only when the clay is in a solid-state. For other states (semi-solid, plastic, and liquid), the uplift capacity is high when the clay layer is above the sand layer. The critical condition is found in this work when the clay soil is in a liquid state and in contact with the anchor. Also, the failure pattern in layered soils was determined for all model tests.