The Effects of a Setback on the Bearing Capacity of a Surface Footing near a Slope

The effects of setback on the ultimate bearing capacity of rigid surface footings placed on the crest of the slope are evaluated using a limit-equilibrium-based method. It is shown that the values of the bearing capacity coefficient or correction factor for the ultimate bearing capacity of a footing placed on the crest of a slope can be expressed as linear functions of the setback-to-footing- width ratio up to a certain threshold value namely, (b/B)(subscript t). Beyond this threshold value, the ultimate bearing capacity is the same as those obtained for a similar footing placed on semi-infinite level ground. The value of (b/B)(subscript t) can be uniquely related to the internal friction angle of the foundation soil, φ, regardless of the change in the slope angle, α. Good agreements are obtained between the value of correction factors obtained herein and those reported in the literature. It is also shown that a conventional indirect approach which deals with the effects of a setback using an equivalent surcharge on the slope surface also works well in the sense that the indirect approach generate small errors in the correction factors when compared to those obtained using the direct approach such as the one proposed in the present study.

並列關鍵字

Bearing capacity ； surface footing ； slope ； limit equilibrium method

國際替代計量

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