Problem $1$

$(30$ Points$)$

After the construction of a concrete retaining wall $($Refer to the Figure below$),$

$1000m^3$ of backfill material $($water content of $12\%$ and $G_s=2\mathrm{.}7)$ from a

nearby borrow pit was brought into the excavation behind the wall and

compacted to a final void ratio of $0\mathrm{.}8.$ If the soil in the borrow pit has a void

ratio of $1\mathrm{.}1,$

a$)$ Determine the volume of solids and volume of the compacted backfill.

b$)$ If the water content in the compacted backfill is $16\%,$ determine the weight

of water that needs to be added

c$)$ Determine the change in degree of saturation with respect to backfill

material characteristics