Bearing Capacity of Footings on Anisotropic Soils

Using the method of characteristics the ultimate bearing capacity of rough strip footings on soils in which cohesion is anisotropic, and increases linearly with depth, is studied. The values of bearing capacity factor \IN\dc\N are presented for different rates of increase of cohesion, \IB\dc\N, with depth, and for different values of coefficient of anisotropy \iK. It is found that for the range of \IB\dc\N values studied when \iK changes from 1.0 to 2.0 the reduction in the value of \IN\dc\N is about 30% to 40%, whereas when \iK changes from 1.0 to 0.8 the increase in the \IN\dc\N value is 15% to 20%. It is also found that in the case of anisotropic and nonhomogeneous soils, the rupture surfaces extend to smaller distances in both horizontal and vertical directions when compared to those in the case of isotropic and homogeneous soils.