Bearing Capacity of Double Box Shaped Skirted Footings on Sand

Rakesh Kumar Dutta; Tammineni Gnananandarao; Vishwas Nandkishor Khatri

Abstract

The double-box-shaped footing with and without skirt and sand-resting pressure settlement behavior was discussed in this paper. Different parameters are normalised skirt depth (0.25 to 1.5), relative sand density (30 to 60 percent) and sand footing interface state (partially rough and rough). Results of this study showed that a general and local shear failure was observed at a relative density of 50 percent and 60 percent, and 30 percent and 40 percent, respectively, regardless of the roughness condition of the skirt-free footing shaped double box. Regardless of the roughness of the unskirted double box shaped footing, the settlement ratio at failure was about 9 % for both the partially rough and rough interface. The application of the skirt to the double box shaped footing further improved the pressure settlement behvaiour with the increase in the normalised skirt depth. The increase observed with the addition of the skirt in the bearing capacity of the double box shaped footing was around 1.27 to 4.64 times the bearing capacity of the double box shaped footing without skirt keeping other parameters the same. The improvement in the bearing capacity ratio in double box-shaped skirted footing decreased with the increase in relative density and the peak improvement in the bearing capacity ratio was observed at a relative density of 30 % with the inclusion of the skirt for the partially rough condition. The settlement was found to decrease with the increase in the normalized skirt depth at a given pressure below the double box shaped footing. Finally, an attempt was made to compare the results of this study with the literature reported multi-edge H-shaped skirted footing

Abstract

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