Lower-bound analytical solution for bearing capacity factor using modified Hoek-Brown failure criterion

The bearing capacity factor N-sigma of a strip footing resting on homogenous rock masses is investigated by a lower-bound approach with the modified Hoek-Brown failure criterion. Three types of admissible stress fields-three stress legs, nine stress legs, and infinite stress legs - are used to calculate the bearing capacity factor. The new analytical expressions are derived, and the results are compared with existing solutions. Agreement shows that the new analytical expressions are effective for evaluating the bearing capacity factor. The influences of parameters in the modified Hoek-Brown failure criterion on the bearing capacity are discussed. Design tables are presented for practical use in engineering.