Bearing Capacity of Clays whose Cohesion Increases Linearly with Depth

The method-of-characteristics approach is used in general to find the ultimate bearing capacity of footings on soils whose cohesion is homogeneous and isotropic. In this technical note, the method is further developed and equations along the characteristics are derived for the soils, whose cohesion varies linearly with depth under ϕ = 0 condition. Using these characteristic equations, the ultimate bearing capacity of strip and circular footings placed at a depth have been obtained. The numerical results are presented in the form of bearing capacity factor $N_c$ versus nondimensional depth of footing. The results show that $N_c$ varies linearly with nondimensional depth of footing for a given constant linear increase in cohesion with depth. The bearing capacity factor $N_q$ is found to be constant and equal to 1.0.