This example concerns a strip and column footing design in sand, considering the effects of groundwater. The loading given by the structural engineer happens to be $15,000lb$ per linear foot of the wall. The average SPT $(N)$ value is found to be $7,$ which relates to a friction angle of $30$ for fine sands.

The groundwater is $2ft$ below the ground surface. The bottom of the roting is placed $3ft$ below the ground surface to provide protection against frost. Compute the bearing capacity of a $4ft$ wide strip footing. See Fig. $5\mathrm{.}24.$

Figure $5\mathrm{.}24$ Shallow foundation $($groundwater effect considered$)$