A 20-kips axial load is applied to a short wooden post which is supported by a concrete footing resting on undisturbed soil as shown. Determine the size "b" of the concrete footing if the average bearing stress on the soil is not to exceed 30 psi.
a. b = 25.8 in.
b. b = 22.4 in.
c. b = 18.3 in.
d. b = 15.8 in.
The solution determines the size of a concrete footing of an axial load.