$5\mathrm{.}7$ Standard Proctor compaction test results on a sandy

clay $(35\%$ sand, $55\%$ clay, and $10\%$ silt$),$ taken from a

borrow pit, are given in the following table.

The sandy clay in the borrow pit has a porosity of $65\%$

and a water content of $5\mathrm{.}2\%.$ A highway embankment is

to be constructed using this soil.

$($a$)$ Specify the compaction $($dry unit weight and water

content$)$ to be achieved in the field. Justify your

specification.

$($b$)$ How many cubic meters of borrow pit soil are

needed for $1$ cubic meter of highway fill?

$($c$)$ How much water per unit volume is required to

meet the specification?

$($d$)$ How many truckloads of soil will be required for a

$100,000-m^3$ highway embankment? Each truck has

a load capacity of $22\mathrm{.}5m^3$ and regulations require a

maximum load capacity of $90\%.$

$($e$)$ Determine the cost for $100,000m^3$ of compacted

soil based on the following:

Purchase and load borrow pit material at site, haul

$2km$ round$-$trip, and spread with $200HP$ dozer $=$

$$\frac{15}{m^3}$; extra mileage charge for each $km=$$$\frac{0\mathrm{.}5}{m^3}$;

round$-$trip distance $=10km$; compaction $=$$$\frac{1\mathrm{.}02}{m^3}.$