Experimental study on the performance of geogrid-reinforced soil (GRS) walls under monotonic footing loading

Geogrid-reinforced soil (GRS) is a widely employed compound material in the construction of retaining walls. This paper presents a set of reduced-scale model tests to study the performance of GRS walls with dry backfill under monotonic footing loading, varying parameters such as wall inclination angle and the number of reinforcement layers. Lateral deflections of the retaining wall, bearing capacity of the footing and the failure mode of the soil were analysed. The results indicated that augmenting the reinforcement layers will lessen wall lateral deflections, and increasing the angle of inclination could significantly enhance ultimate bearing capacity of the footing. A linear relationship was found between the overall lateral deflections of the retaining wall and the footing settlement. The failure of geogrid could lead to a breakdown in the connection between the geogrid and the soil, consequently causing local failure. The failure modes of the GRS wall under strip footing was composed of shear failure in the reinforcement layer and spiral failure in the weak layer. At last, the logarithmic spiral analysis method was modified slightly to calculate the ultimate bearing capacity. The analytical solution and the outcomes derived from experimental models exhibit a high level of concordance.