Compressive load response of geogrid-reinforced fine, medium and coarse sands

Abstract

This paper presents data obtained from a series of laboratory plate load tests performed on geogrid-reinforced sand beds. Fine, medium and coarse sands were used as test sand beds. Circular geogrids of diameter 120 mm were used as reinforcement layers. Improvement in load–settlement response was studied. The test sand beds were compacted to a relative density of 50%. A surface footing plate of diameter 60 mm was used as the shallow foundation. It was found that the horizontal geogrid reinforcement improved the load–settlement response. The applied load for a deformation of 0.5 mm in the case of geogrid-reinforced fine sand, medium sand and coarse sand was, respectively, 83 N, 44 N and 87 N, whereas it was 63 N, 38 N and 47 N when the sands were unreinforced. Load–settlement response was found to improve further with increase in number of geogrid layers and with decrease in spacing between them. Load improvement ratio (LIR), defined as the ratio of load for a given settlement in geogrid-reinforced case to that for the same settlement in unreinforced case, increased with number of geogrids ( n) for all sands, but the improvement was significant in the case of coarse sand.