Effects of Embedment Depth of Foundations on Ultimate Bearing Capacity of Rock Masses

The embedment depth of footings is an essential factor affecting the bearing capacity of base material. In most bearing capacity determination methods, the effect of the embedment depth was considered by applying an equivalent vertical stress to the ground surface. This simplifying assumption excludes the effect of the shear strength of the rock mass at the levels above the footing base. In the present paper, a bearing capacity equation was obtained for rock masses in which, the effect of the embedment depth of the footing was considered directly without replacing its equivalent vertical stress. Using the upper bound method, the Hoek–Brown failure criterion was employed for the rock mass. The results revealed that the incorporation of the embedment depth results in considerably greater bearing capacity than the cases in which, an equivalent surcharge was used. Therefore, it is important to consider the footing embedment depth for optimal design of foundations.