Abstract: The use of high-quality materials and the strengthening of soil layers, especially in areas with poor bedding, are among the most important factors in stabilizing and achieving the useful life of building structure. An experimental study on a strip footing coated with unreinforced, geogrid-reinforced, and folded geogrid layers of fine sand is presented in this paper. Testing procedures evaluate variables such as the number of planar geogrid layers, the position of the folded geogrid within the soil, the thickness of the geogrid folded layer, the overlap lengths of a folded geogrid, the spacing within folded layers of geogrid, and several layers of geogrid. Compared to planar geogrid reinforced sand, folded geogrid reinforced sand performed better as a result of static loading. In addition, a critical region was found at a certain depth under the footing, where a geogrid folded results in increased footing settlement. This critical area affects the behaviour of sandy soils with low footing widths. Moreover, the results show that the embedment depth and thickness of the folded geogrid are 0.41 and 0.20 of the footing widths, respectively. By increasing the number of folded geogrid layers, the settlement rate is significantly reduced. It was determined that wrapping the reinforced cases around the surrounding frames significantly improved the bearing capacity, reduced settlement, and allowed them to be used in tight spaces.

Key words: geosynthetic, strip footing, geogrid wraparound, geogrid planar, sand, bearing capacity, settlement behaviour