Chapter 7, Problem 7.12QPP

A 5 ft wide, 8 ft long, 3 ft deep footing supports a downward load of 200 k and a horizontal shear load of 25 k. The shear load acts parallel to the 8 ft dimension. The underlying soils have $c\text{'}=220{\text{lb/ft}}^{\text{2}},\varphi \text{'}=28°,$ and $\gamma =123{\text{lb/ft}}^{\text{3}}.$ Using an effective stress analysis, compute the factor of safety against a bearing capacity failure.