Laboratory Study of the Behavior of Geogrid-Reinforced Strip Foundations with Inclined Loading

Inclined loading reduces the bearing capacity of the foundation. Planar reinforcements, like geogrids, can compensate for the inclined loading's reduced bearing capacity. The current study designed and developed a system capable of loading at an angle of up to 20 degrees. Loading tests were conducted on a strip foundation with dimensions of 650 x 100 mm and a thickness of 30 mm using this system. The test box has a plan dimension of 670 x 1180 mm and a height of 700 mm. The effect of loading type, vertical reinforcement distance from the soil surface, reinforcement width, the number of reinforcement layers, and load inclination on the bearing capacity was investigated. The tests were conducted in reinforced and unreinforced environments. The results indicate that the maximum bearing capacity is obtained when the first reinforcing layer is 0.3 times the width of the loading plate away from the soil surface. By increasing the width of the reinforcement, the bearing capacity of the foundation increased, and the foundation failed in a further settlement. The inclined loading tests used five different angles of 0, 5, 10, 15, and 20 degrees. The results indicated that the bearing capacity decreases as the load inclination increases. At greater angles, the reduction in bearing capacity is greater. By increasing the number of soil reinforcement layers, the bearing capacity of the soil is increased at all load inclinations. Finally, new relationships for estimating the load inclination coefficient were presented to determine the bearing capacity of strip foundations with reinforced soil.