Model testing of strip footings with structural skirts

Tests on footing models were carried out to study the behaviour of strip footings with structural skirts resting on sand. The use of structural skirts improved the bearing capacity of strip footings by a factor of up to three. The improvement depends on the geometrical and structural properties of the skirts and footing, and the soil characteristics and interface conditions of the soil-skirt-foundation system. To account for these factors, a modified bearing capacity equation was proposed for skirted strip foundations on dense sand by the authors. The predictions of the proposed equation are in excellent agreement with the experimental results. The experimental results showed that the use of structural skirts reduced the settlement by a factor of up to three depending on the skirt depth, geometrical properties of the skirt and footing, soil characteristics and the applied load. The structural skirts modified the load-settlement curve for the footing by increasing the strain at failure to about 22%.