Footing on the Crest of Slope: Slope Stability or Bearing Capacity?

Abstract

A footing on the crest of a slope may be considered as either a slope stability or a bearing capacity problem. Traditional slope stability analysis delivers the safety factor with respect to shear strength, while traditional bearing capacity analysis delivers the safety factor with respect to loading. These two strategies indicate quite different safety levels, even when applied to the same problem. Eurocode 7 (EC7) allows for the use of both strategies. Indeed, in the limit state framework of EC7 slope stability and bearing capacity problems do not share the same partial factors. Since, EC7 does not have a special provision for the problem of a footing on the crest of slope, the question whether it is a bearing capacity or a slope stability problem remains. The parametric studies presented in this paper based on EC7 design guidelines and different factoring strategies, shows that the kind of failure mechanism observed strongly depends on the magnitude and position of the footing loading.