3-1. Estimate the actual bucket load in bank measure for a hydraulic excavator – backhoe whose heaped bucket capacity is 2.10 CY (1.6 CM). The machine is excavating sand and gravel

3-1. Estimate the actual bucket load in bank measure for a hydraulic excavator – backhoe whose heaped bucket capacity is 2.10 CY (1.6 CM). The machine is excavating sand and gravel

3-3. A 2-CY (1.53 CM) dragline is being used to excavate a canal in common earth. The average swing angle is 70º, the average depth of cut is 8.9 ft. (2.7 m), and the job efficiency is 50 min/hr. Estimate the dragline’s hourly production in loose measure.

3-5. An hydraulic excavator-backhoe is excavating the basement for a building. Heaped bucket capacity is 1.5 CY (1.15 CM). The material is common earth with a bucket fill factor of 0.90. Job efficiency is estimated to be 50min/hr. The machine’s maximum depth is of cut 24 ft (7.3 m) and the average digging depth is 13 ft (4.0 m). Average swing angle is 90º. Estimate the hourly production in bank measure.

3-6. A small hydraulic excavator will be used to dig a trench in soft clay (bucket fill factor = 0.90). The minimum trench size is 24” (0.61 m) wide by 6’ (1.83 m) deep. The excavator bucket available is 30” (0.76) wide and has a heaped capacity of ¾ CY (0.57 CM). The maximum digging depth of the excavator is 17.5’ (5.3 m). The average swing angle is expected to be 90º. Estimate the hourly trench production in LF (m) if the job efficiency is 50 min/hr.

4-2. The tractor-scraper whose travel-time curves are shown in Figures 4-4 and 4-5 hauls its rated payload 4,000’ (1220 m) up a 5% grade from the cut to the fill and returns empty over the same route. The rolling resistance factor for the haul road is 120 lb/ton (60kg/t). Estimate the scraper travel time.

4-6. How many hours should it take an articulated wheel loader equipped with a 4 CY (3.06 CM) bucket to load 3,000 CY (2294 CM) of gravel from a stockpile into rail cars if the average haul distance is 300’ (91.5 m) one way? The area is level with a rolling resistance factor of 120 lb/ton (60 kg/t). Job efficiency is estimated at 50 min/hr.

5-1. The data in the accompanying table resulted from performing Modified Proctor Tests on a soil. Plot the data and determine the soil’s laboratory optimum moisture content. What minimum field density must be achieved to meet job specifications which require compaction to 90% of Modified AASHTO Density?

5-5. Estimate the production in compacted CY (CM) per hour of a self-propelled tamping foot roller under the following conditions: average speed = 5 mph (8.0 km/hr), compacted lift thickness = 6” (15.2 cm), effective roller width = 10’ (3.05 m), job efficiency = 0.75, and number of passes = 8.