The layout shown is for a subdivision that requires the following cuts and fills:
|
Requirement (cy) |
|
|
Cut A |
100,000 |
|
Cut B |
60,000 |
|
Cut C |
80,000 |
|
Fill D |
140,000 |
|
Fill E |
70,000 |
|
Fill F |
50,000 |
a) Assume that the bridge shown has not yet been constructed. Determine the solution for the minimum cost for this job. The borrow pit at H will sell you up to 60,000 cy of fill for $0.05/cy. Thereafter, he will sell up to an additional 40,000 cy of fill for $0.08/cy, but no more. Spoils pit G will accept up to 30,000 cy of spoils at no charge, but will charge $0.02/cy thereafter, without limit. Hauling charges are $0.03/cy per mile for North-South travel, and $0.02/cy/mile for East-West travel. All distances shown on the map are miles.
b) Solve the problem again, assuming that the bridge is able to be completed before you start work.
Hint: Borrow pit H can be broken up into two separate pits: HL (H low cost) and HH (H high cost.) Likewise, Spoils pit G can be broken up into two separate pits: GF (G free) and GL (G low cost.)
Solution can be found here. Cost coefficients courtesy of Mr. Armand and not guaranteed. Check them yourself. Errors reported to lowery@tamu.edu will be acknowledged.