Model studies of embedded circular footing on geogrid-reinforced sand beds.

This paper describes laboratory model tests to determine the bearing capacity of an embedded circular footing supported by multiple layers of geogrid-reinforced sand beds. The embedment depth ratio of the footing was varied from zero to 06. The tests were conducted with one variety of geogrid in sand compacted to 70% relative density. Besides load settlement data, deformations on fill surface, strain in geogrid layer and pressure distribution in soil subgrade (below the geogrid layers) were measured. The test results demonstrate that the ultimate bearing pressure increases with embedment depth ratio of the foundation. With the provision of multiple layers of geogrid reinforcement in the sand bed, high-performance improvement is obtained, in terms of both increase in bearing capacity and reduction in surface deformation. Also, the footing pressure is redistributed more uniformly over a wider area on the subgrade soil. Strain measurements in the geogrid layers indicate that the geogrid reinforcement is more effective in the region below the footing width. [ABSTRACT FROM AUTHOR]