. Two choices for borrow soils are available:
Borrow A Borrow B
Density in place 115 pcf 120 pcf
Density in transport ? 95
Void ratio in transport 0.92 ?
Water content in place 25% 20%
Cost to excavate $0.20 /yd3 $0.10 /yd3
Cost to haul $0.30 /yd3 $0.40 /yd3
Gs 2.7 2.7
Maximum Proctor dry density 112 pcf 110 pcf
Note: “In place” indicates when the soil was in the original, natural location.
It will be necessary to fill a 200,000 yd3 depression, and the fill material must be compacted to
95% of the standard Proctor (maximum) density. A final 10% moisture content is desired in
either case.
a. What is the minimum volume of borrow from each site needed to fill the depression?
b. What is the minimum quantity (volume) from each site to haul?
c. What soil would be cheaper to use?