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Column Pad Foundation

$$ PAD FOOTING: $6^{\text{'}}W{6}^{\text{'}}L{15}^{\text{'}\text{'}}H$

$$ PIER: $1^{\text{'}}$ W $1^{\text{'}}L{2\mathrm{.}75}^{\text{'}}H$

$$ Design depth $($bottom of footing$)=4^{\text{'}}$ below grade

$$ Allowed excavation $=2^{\text{'}}$ wider than footing for each side for working ror

$$ Assume vertical excavation sidewalls $($cohesive soil w$/$no shoring$)$

What is the volume of excavation $($in$-$place cubic yards$)$ required?

What is the volume of the concrete column pad foundation $($pad and pier$)$ in cubic yards?

Using your answers from questions $1$ and $2,$ what is the volume of compacted structural backfill $($inplace cubic yards$)$ needed to fill in the excavation around the foundation up to grade?

Due to unsuitable soils found at the depth of the proposed footing, we need to remove an additional $3^{\text{'}}$ of material below the footing and replace it with compacted structural backfill.

$4.$ Considering guidelines for over$-$excavation $(1$ foot horizontally for every $1$ vertical foot$),$ what are the dimensions $(L,W,$& & $)$ in feet of the new excavation? $($If your over$-$excavation calculations result in less than a $2^{\text{'}}$ increase for the $L$ and $W,$ use only the $2^{\text{'}}$ working room allowance. Otherwise, do not include the working room allowance$).$

$5.$ Using your answer from question $4,$ what is the volume of this excavation $($in$-$place cubic yards$)?$

$6.$ Using your answers from questions $1$ and $5,$ what is the additional amount $($in$-$place cubic yards$)$ of soil that has to be excavated?

$7.$ Using your answers from questions $2$ and $5,$ what is the volume of compacted structural backfill $($inplace cubic yards$)$ needed to fill in the excavation beneath and around the foundation up to grade?

$8.$ Using your answers from questions $3$ and $7,$ what is the additional amount $($in$-$place cubic yards$)$ of compacted structural backfill needed to fill in the excavation beneath and around the foundation up to grade?