$16-23)($a$)$ Using the Barnes slope stability tables for excavated slopes, determine if a face inclination of $1$ horizontal to $1$ vertical is safe for a $16-m-$high slope in soils where $$ is $18\mathrm{.}75k\frac{N}{m^3},c^{\text{'}}$ is $15$kPa,$$ is $25,$ and the groundwater table is $8$ m below the top of the slope $($or $8$ m above the toe of the slope$).$

$($b$)$ Determine the slope factor of safety if the excavation for the conditions described in part $($a$)$ is made with an inclination of $2$ horizontal to $1$ vertical.

$($c$)$ Can this excavated slope be made with an inclination of $1\mathrm{.}5$ horizontal to $1$ vertical and still be safe against a slide failure?