Effect of Load Inclination on the Bearing Capacity of Jointed Rock Foundations

In this paper, upper bound method of limit analysis is used to obtain the vertical and inclined bearing capacity of rock masses containing two orthogonal joint sets. The spacing of the joint sets is assumed to be large compared to the footing width. Different orientation angles are considered for the joints, and the Mohr–Coulomb failure criterion is employed for both the intact rock and the joint sets. Analytical expressions are derived for the bearing capacity of a strip footing resting on a jointed rock subjected to vertical loading. Then, the effect of load inclination on the bearing capacity is incorporated into the analytical equations by means of inclination coefficients. The findings are compared to the other solutions existing in the literature. The results of this study show that increasing the joint friction angle leads to decreasing the inclination coefficient. Moreover, increasing the joint orientation angle with respect to the horizontal direction results in decreasing the inclination coefficients. The obtained results are presented in tabular form that can be used easily for practical purposes.