Experimental study and numerical analysis of the bearing capacity of strip footing improved by wraparound geogrid sheets

A simplified technique was considered to study the effects of incorporating fully wraparound geogrids on the behavior of fine sand soil under a strip footing. Numerical and experimental work were used to estimate this performance. This study has shown that some parameters affect the behavior of reinforced soil with folded geogrid inclusions. In addition, the parametric study was extended to include a fully folded geogrid layer, the embedment depth of the fully folded geogrid, the thickness of a fully folded geogrid, the distribution of stresses in the soil mass, and the additional lateral constriction effect. The significant effects of introducing one or two fully-folded geogrid layers in denser fine sand have been assessed by conducting a series of strip plate load tests. The failure modes were proposed using the finite element method under plane strain conditions. As a result, a modified expression was recommended to develop an improved soil bearing capacity with a fully folded geogrid inclusion. The predicted expression provides a good agreement with the experimental findings; therefore, the approximate error rate was approximately 7%. The bearing capacity increases more with the inclusion of a fully folded geogrid than with planar reinforcement layers. Although the ratio of the length of the geogrid concerning footing width (L/B) of 5 and 7 has the same effect on the settlement values, the significant effect is associated with fully folded geogrid layers of shorter length. The presence of fully folded geogrid reinforcement at burial depths of (u = 0.4B and d = 0.2B) below the surface of the sand layer plays a major role in reducing the vertical normal settlements and significantly improves the bearing capacity.