Bearing capacity of shallow foundations on rocks obeying a modified Hoek-Brown failure criterion

The bearing capacity of shallow foundations resting on a modified Hoek-Brown rock: mass is investigated within the framework of the kinematic approach of limit analysis theory. At the rock material nivel, closed-form expressions are obtained for the support functions of the rock failure criterion. These expressions of the H-functions are then applied to derive upper bounds estimates of the load-bearing capacity by implementing two classes of failure mechanisms. The numerical results are first compared to existing limit analysis solutions, showing the efficiency of the present approach. The effects of the loading parameters are then discussed at the light of these preliminary results. The results are compared with finite element limit analysis solutions, emphasizing the efficiency of the present approach. Design tables are finally presented for practical use in rock engineering. (C) 2007 Elsevier Ltd. All rights reserved.