1. A general contractor is asking your company to bid on the earthmoving bid item of a project (that will make you a sub-contractor). The bid item is to move 85,000 BCY of a sandy clay soil with a unit weight of 2,900 lb/BCY an average distance of 4,600 feet. The bid item is just to load, haul and spread; no compaction or other services. Your site inspection revealed that the designated haul road will quickly become a rutted dirt roadway with 2 of tire penetration with no anticipation of any maintenance. Your company has the 627K tandem powered push- pull scrapers available for this project. They are in the push-pull configuration and will be operated accordingly without a dozer. Through prior experience and tables, you estimate a 0.87 soil swell factor and time efficiency will be 50 minutes per hour. Find: a) The cycle time for one scraper. Calculate scraper speed using formulas since CAT HB Rimpull chart is not precise for this variable. Haul road: 700' at -2% 900' at +3% 600' at -7% 2400' at +1% b) How many scrapers to use to meet the two-week deadline given by the general contractor (so, 80 operation hours; disregard mobilization and demobilization time) c) Total production rate per hour. d) Calculate your bid amount in total and $/BCY if: The O&O cost of one scraper with operator is $175/hr. Support staff and other equipment cost is $260/hr. Mobilization, Demobilization, Overhead, and Profit are 18% over the total cost. O O O Homework Format Notes: . your work. . . Show all steps of Organize and label each heading and step. Write raw (given) equations. Show intermediate steps with results and double underline. Show final answers for each section with a box around it. O . 1. A general contractor is asking your company to bid on the earthmoving bid item of a project (that will make you a sub-contractor). The bid item is to move 85,000 BCY of a sandy clay soil with a unit weight of 2,900 lb/BCY an average distance of 4,600 feet. The bid item is just to load, haul and spread; no compaction or other services. Your site inspection revealed that the designated haul road will quickly become a rutted dirt roadway with 2 of tire penetration with no anticipation of any maintenance. Your company has the 627K tandem powered push- pull scrapers available for this project. They are in the push-pull configuration and will be operated accordingly without a dozer. Through prior experience and tables, you estimate a 0.87 soil swell factor and time efficiency will be 50 minutes per hour. Find: a) The cycle time for one scraper. Calculate scraper speed using formulas since CAT HB Rimpull chart is not precise for this variable. Haul road: 700' at -2% 900' at +3% 600' at -7% 2400' at +1% b) How many scrapers to use to meet the two-week deadline given by the general contractor (so, 80 operation hours; disregard mobilization and demobilization time) c) Total production rate per hour. d) Calculate your bid amount in total and $/BCY if: The O&O cost of one scraper with operator is $175/hr. Support staff and other equipment cost is $260/hr. Mobilization, Demobilization, Overhead, and Profit are 18% over the total cost. O O O Homework Format Notes: . your work. . . Show all steps of Organize and label each heading and step. Write raw (given) equations. Show intermediate steps with results and double underline. Show final answers for each section with a box around it. O
