The difficulty that faces the geotechnical engineers how to find the alternative and effective method to improve bearing capacity and reduce foundation settlement. Therefore, the skirt is considered one of the methods to improving the shallow foundation bearing capacity on different soil. The mechanism of skirt work is confinement soil below the foundation and decrease settlement of the foundation. Soil engineers are worked to devise this method as an alternative to pile foundation for conventional buildings. This paper reviews most of these studies of skirted foundations with different types of soil including laboratory tests, field tests, centrifuge models, numerical method and theoretical analysis; these studies are used in investigation the behaviors skirted foundations.
Increasing the bearing capacity of shallow foundations is a significant challenge in the urban environment due to increased population growth. This paper presents the bearing capacity of circular foundations encircled by a diaphragm wall. In this study, the effects of diaphragm wall depth (0.5 D, D, 2 D) (D is the foundation diameter) of the foundation on the bearing capacity of the foundation are investigated. Varying relative densities of sand soil (loose, medium, and dense) are utilized. The results of the experimental tests show that the diaphragm wall possesses an influence upon the settlement and the foundation bearing capacity. Where, the capacity of bearing increased as the diaphragm wall depth increased. On the other side, increasing the depth leads to a decrease in the settlement ratio of about 57%. The results of experimental work also demonstrated that the best depth is between D and 2D for all types of relative densities