Behaviour of Interfering Embedded Footings Laid in Unreinforced and Reinforced Sand Medium

According to the literature, the current understanding of the interference effect on the performance of footings is with respect to surficial footings. In practice, however, the footings are laid below the ground surface. In this study, the interference behaviour of two identical strip and square footings embedded in a cohesionless, homo­geneous soil medium was examined by performing 72 laboratory model tests. The sand bed was prepared using rainfall technique and reinforced with a single biaxial geogrid layer. Parameters such as footing shape, embedment depth and the spacing between the footings were altered. Using the observed data, multiple regression analysis established a relationship between interference variables related to load-carrying capacity/settlement footing spacing and embedment depth for unreinforced and reinforced soil medium. The test results show that the embedment depth of ultimate bearing capacity and settlement affects interfering footings more than surficial footings. Strip footings are affected to a greater extent than square footings. The load-carrying capacity of two footings increases due to the enhancement of the zone of interference by 12.2% and 39.6% for the strip and square footings respectively.