Problem
A limestone formation, average depth of 2.4 ft. is exposed over the full 80-ft width and 23,700-ft length of a highway cut Seismic investigations indicate that the reek layer has a seismic velocity of 5.500 fps. The contractor proposes to loosen this rock by using a single-shank ripper on a power shift, track-type tractor. It is estimated that job conditions relative to the rock characteristics are average or midway between advent and Ideal. A 40-min hour working efficiency should be obtainable while the ripper is actually in production. but it is estimated that the tipper will be cut of service for repairs for 5% of the total hours that the ripper =Id be used on the job (i.e.. availability 0(0.95). It is further estimated that the ripper will be Out of service due to adverse weather for 20% of the same total bows. The contractor wishes to explore the use of two 370-hp tractors for the ripping operations. OW cost including rippers, is estimated at 579.82 per working hour for each tractor. Each machine is to be charged against the job at 60% of its normal OW rate during working hours when the equipment is not used because of advent weather or scheduling ProNerns, but will not be charged against the job when the equipment is down for repair. The opera car's wage, paid during hours worked and tows when the equipment is being repaired. is $14.30 per hour. Associated charges against the ripping operation for the foreman and mechanic are estimatedto be $25 per nominal (ie.. regularly scheduled. including downtime for repairs and advent weather) working bows. Move-in and move-ow costs, combined, are estimated to be S200 per tractor. Calculate the total time in weeks, based on a normal 40-hr workweek, to loosen the rock cut, and calculate the total loosening cost. in dollars per boy. (production 0.205 =Mir. total cost $109,870. cheaper to use two dozers, 396.661)
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.