Upper bound solution for the bearing capacity of rock masses considering the embedment depth

The effect of the embedment depth is one of the most important issues in calculating the bearing capacity. The results of the previous studies show that in most cases, it was assumed that the footings are rested at the ground surface and the effect of the embedment depth was considered by applying an equivalent surcharge load to the ground surface. In this paper, the influence of the embedment of the footings on the bearing capacity of weak rock masses was investigated using the upper bound method of limit analysis. The modified Hoek-Brown failure criterion was used for the rock mass. The embedment depth of the footings was considered directly in the upper bound calculations. According to the obtained results, considering the embedment depth results in increasing the ultimate bearing capacity, which cannot be anticipated correctly in the methods which replace the embedment depth by an equivalent surcharge. The results of this paper were presented in the form of a design table that can be used easily in practical applications.y