You are planning to excavate the 30-foot by 40-foot basementarea of a house to a depth of 10- feet in common earth. An 18-inchwide, 5-foot deep, 100-foot long sewer trench will also berequired. You have at your disposal a hydraulic excavator with a ½cubic yard 24-inch wide bucket. The excavator’s maximum diggingdepth is 14.7-feet and the average angle of swing is estimated tobe 75-degrees. Job efficiency is expected to be 45-minutes per hourwith costs for the excavator being $50 per operating hour and $250each to transport the excavator to the site and return it to theequipment yard after trench and basement excavations are complete.Allow for 5-percent overage in basement excavations and 10-percentoverage beyond the capabilities of the equipment for the trench.After the foundation has been placed and backfilled, and the trenchhas been covered, it is estimated that 400 cubic yards of loosematerial will remain in a single stockpile that will need to bemoved offsite. You will have at your disposal a crawler crane witha 0.90 LCY clamshell to load a series of dump trucks. Cycle timefor the clamshell is estimated to be 45-seconds with the same45-minute per hour efficiency. Costs for the crane and clamshellare $75 per operating hour and a combined lump sum of $500 tomobilize and demobilized.

ASSUMPTION(S)/CONDITION(S)  Excavator bucket heap accounts formaterial swell. You do not need to account for swell and/orshrinkage in your calculations.

 When using tables to determine appropriate factors to use inyour calculation and a range is given, use the middle value betweenthe high and low.

 All material excavated for the trench will be used duringbackfilling operations. There are no spoils remaining from thetrench portion of the excavation.

 Assume that sufficient dump trucks will be available intowhich to load the remaining basement spoils. That is, there will beno downtime waiting for trucks to become available.

 No partial workdays are allowed. Should less than a full daybe required to all or a portion of the work, payment for the full8-hours is still required.

QUESTION 1 How much material is required to be excavated from:a) The basement, and b) The trench?

QUESTION 2 What is the time required to excavate a) thebasement, and b) the trench?

QUESTION 3 What are the total costs and unit costs to excavate:a) The basement, and b) The trench?

QUESTION 4 How many hours does it take to load the remainingexcavation spoils to transport them off-site?

QUESTION 5 How much does it cost to mobilize, demobilize, andload the excavation spoils in total and as a unit cost?