Load-settlement response of strip footing overlaid fine sand strengthened with different arrangements of geogrid inclusions

ABSTRACT This study reports the results of experiments conducted on strip foundations with and without reinforced geogrids over fine sand and with a wraparound geogrid arrangement. A load up to 25 kN was applied to the strip foundations to determine the loading-settlement response. These tests examined the number of planar and folded geogrid sheets, the placement of folded geogrids in the soil bed, the thickness of folded geogrid sheets, the length of wraps and overlaps, and the spacing between folded and planar geogrid sheets. The results indicate that the performance of the foundations due to static loading is better for folded geogrid-reinforced sand than for planar geogrid-reinforced sand. Overall, the results demonstrate that reinforced soil foundations with sufficiently folded geogrid layers behave much stiffer and thus can support higher loads with a lower settlement than planar reinforced soils. Moreover, the results indicate that the values of the embedment depth of the overlap element (d), the lower part (D), and the thickness (x) of the folded geogrid are 0.2, 0.4, and 0.2 of the foundation widths (B), respectively. As a result, by increasing the number of geogrid layers, the settlement rate is reduced significantly, and it is recommended that these layers be placed vertically without vertical spacing (h/B = 0).