LOOKSFAM

Find the swell of a soil that weighs 1661 kg/m3 in its natural state and 1186 kg/m3 after excavation.

Find the swell of a soil that weighs 1661 kg/m3 in its natural state and 1186 kg/m3 after excavation.

40%

Find the shrinkage of a soil that weighs 1661 kg/m3 in its natural state and 2077 kg/m3 after compaction.

20%

A soil weighs 1163 kg/LCM, 1661 kg/BCM, and 2077 kg/CCM. Find the load factor and shrinkage factor for the soil.

Load factor = 0.70 Shrinkage factor = 0.8

A soil weighs 1163 kg/LCM, 1661 kg/BCM, and 2077 kg/CCM. How many bank cubic meters (BCM) and compacted cubic meters (CCM) are contained in 593,300 LCM of this soil?

bank vol. = 415,310 BCM; compacted vol. = 332,248 CCM

Find the base width and height of a triangular spoil bank containing 76.5 BCM if the pile length is 9.14 m, the soil’s angle of repose is 37°, and its swell is 25%.

B = 7.45 m; H = 2.80 m

Find the base diameter and height of a conical spoil pile that will contain 76.5 BCM of excavation if the soil’s angle of repose is 32° and its swell is 12%.

D = 10.16 m; H = 3.17 m

Find the volume (bank measure) of excavation required for a trench 0.92 m wide, 1.83 m deep, and 152 m long. Assume that the trench sides will be approximately vertical.

𝟐𝟓𝟓 𝐁𝐂𝐌

Estimate the actual bucket load in bank cubic meters for a loader bucket whose heaped capacity is 3.82 m3. The soil’s bucket fill factor is 0.90 and its load factor is 0.80.

𝟐.𝟕𝟓 𝐁𝐂𝐌

Find the expected production in loose cubic meters (LCM) per hour of a small hydraulic excavator. Heaped bucket capacity is 0.57 m3. The material is sand and gravel with a bucket fill factor of 0.95. Job efficiency is 50 min/h. Average depth of cut is 4.3 m. Maximum depth of cut is 6.1 m and average swing is 90. Hint: Cycle output = 250 cycles/60 min Swing-depth factor= 1.00

𝟏𝟏𝟑 𝐋𝐂𝐌/𝐡𝐫

Find the expected production in loose cubic meters (LCM) per hour of a 2.3-m3 hydraulic shovel equipped with a front-dump bucket. The material is common earth with a bucket fill factor of 1.0. The average angle of swing is 75° and job efficiency is 0.80. Hint: Standard cycles = 150/60 min Swing factor = 1.05

𝟐𝟗𝟎 𝐋𝐂𝐌

Determine the expected dragline production in loose cubic meters (LCM) per hour based on the following information: Dragline size = 1.53 m3 Swing angle = 120° Average depth of cut = 2.4 m Material = common earth Job efficiency = 50 min/h Soil swell op = 25% Hint: Ideal output = 176 BCM/h Swing-depth factor = 0.90

𝟏𝟔𝟓 𝐋𝐂𝐌/𝐡𝐫

Estimate the production in loose cubic meters per hour for a medium-weight clamshell excavating loose earth. Heaped bucket capacity is 0.75 m3. The soil is common earth with a bucket fill factor of 0.95. Estimated cycle time is 40 s. Job efficiency is estimated at 50 min/h.

𝟓𝟑 𝐋𝐂𝐌/𝐡𝐫

A wheel tractor-scraper weighing 91 t is being operated on a haul road with a tire penetration of 5 cm. What is the total resistance (kg) and effective grade when the scraper is ascending a slope of 5%? Hint: RRF = 20 + (6 x cm penetration) GRF = 10 x grade (%) Effective grade = Grade (%) + RRF/10

𝐓𝐨𝐭𝐚𝐥 𝐑𝐞𝐬𝐢𝐬𝐭𝐚𝐧𝐜𝐞 = 𝟗𝟏𝟎𝟎 𝐤𝐠; 𝐄𝐟𝐟𝐞𝐜𝐭𝐢𝐯𝐞 𝐆𝐫𝐚𝐝𝐞 = 𝟏𝟎%

A wheel tractor-scraper weighing 91 t is being operated on a haul road with a tire penetration of 5 cm. What is the total resistance (kg) and effective grade when the scraper is descending a slope of 5%? Hint: RRF = 20 + (6 x cm penetration) GRF = 10 x grade (%) Effective grade = Grade (%) + RRF/10

𝐓𝐨𝐭𝐚𝐥 𝐑𝐞𝐬𝐢𝐬𝐭𝐚𝐧𝐜𝐞 = 𝟎 𝐤𝐠; 𝐄𝐟𝐟𝐞𝐜𝐭𝐢𝐯𝐞 𝐆𝐫𝐚𝐝𝐞 = 𝟎%

A four-wheel-drive tractor weighs 20,000 kg and produces a maximum rimpull of 18,160 kg at sea level. The tractor is being operated at an altitude of 3050 m on wet earth. A pull of 10,000 kg is required to move the tractor and its load. Can the tractor perform under these conditions? Hint: Derating factor = [Altitude (m) - 915]/102 Coefficient of traction = 0.45

𝐁𝐞𝐜𝐚𝐮𝐬𝐞 𝐭𝐡𝐞 𝐦𝐚𝐱𝐢𝐦𝐮𝐦 𝐩𝐮𝐥𝐥 𝐚𝐬 𝐥𝐢𝐦𝐢𝐭𝐞𝐝 𝐛𝐲 𝐭𝐫𝐚𝐜𝐭𝐢𝐨𝐧 𝐢𝐬 𝐥𝐞𝐬𝐬 𝐭𝐡𝐚𝐧 𝐭𝐡𝐞 𝐫𝐞𝐪𝐮𝐢𝐫𝐞𝐝 𝐩𝐮𝐥𝐥, 𝐭𝐡𝐞 𝐭𝐫𝐚𝐜𝐭𝐨𝐫 𝐜𝐚𝐧𝐧𝐨𝐭 𝐩𝐞𝐫𝐟𝐨𝐫𝐦 𝐮𝐧𝐝𝐞𝐫 𝐭𝐡𝐞𝐬𝐞 𝐜𝐨𝐧𝐝𝐢𝐭𝐢𝐨𝐧𝐬.

A crawler tractor weighing 36 t is towing a rubber-tired scraper weighing 45.5 t up a grade of 4%. What is the total resistance (kg) of the combination if the rolling resistance factor is 50 kg/t?

𝟓𝟓𝟑𝟓 𝐤𝐠

A power-shift crawler tractor has a rated blade capacity of 7.65 LCM. The dozer is excavating loose common earth and pushing it a distance of 61 m. Maximum reverse speed in third range is 8 km/h. Estimate the production of the dozer if job efficiency is 50 min/h. Hint: Fixed time = 0.05 min Dozing speed = 4.0 km/h

𝟐𝟕𝟏 𝐋𝐂𝐌/𝐡𝐫

Estimate the hourly production in loose volume (LCM) of a 2.68-m3 wheel loader excavating sand and gravel (average material) from a pit and moving it to a stockpile. The average haul distance is 61 m, the effective grade is 6%, the bucket fill factor is 1.00, and job efficiency is 50 min/h. Hint: Basic cycle time = 0.50 min Travel time = 0.30 min

𝟏𝟔𝟖 𝐋𝐂𝐌/𝐡𝐫

Estimate the production of a single-engine two-axle tractor scraper based on the following information: Maximum heaped volume = 24 LCM Maximum payload = 34,020 kg Material: Sandy clay, 1898 kg/BCM, 1571 kg/LCM, rolling resistance 50 kg/t Job efficiency = 50 min/h Operating conditions = average Single pusher Haul route: Section 1. Level loading area Section 2. Down a 4% grade, 610 m Section 3. Level dumping area Section 4. Up a 4% grade, 610 m Section 5. Level turnaround, 183 m Hint: Travel time: Section 2 = 1.02 min Section 4 = 1.60 min Section 5 = 0.45 min Fixed cycle: Load spot = 0.3 min Load = 0.6 min Maneuver and dump = 0.7 min

𝟏𝟗𝟐 𝐁𝐂𝐌/𝐡𝐫

The estimated cycle time for a wheel scraper is 6.5 min. Calculate the number of pushers required to serve a fleet of nine scrapers using single pushers. Determine the result for both backtrack and chain-loading methods. Hint: Typical pusher cycle time (min) Back-track (single pusher) = 1.5 Chain or shuttle (single pusher) = 1.0

𝐛𝐚𝐜𝐤-𝐭𝐫𝐚𝐜𝐤 = 𝟑; 𝐜𝐡𝐚𝐢𝐧 = 𝟐

Find the expected production of the scraper fleet of the previous problem if only one pusher is available and the chain-loading method is used. Expected production of a single scraper assuming adequate pusher support is 173 BCM/h. Hint: Number of pushers required to fully serve fleet = 1.4

𝟏𝟏𝟐 𝐁𝐂𝐌/𝐡𝐫

Given the following information on a shovel/truck operation, calculate the number of trucks theoretically required and the production of this combination. Shovel production at 100% efficiency = 283 BCM/h Job efficiency = 0.75 Truck capacity = 15.3 BCM Truck cycle time, excluding loading = 0.5 h

𝐍𝐨. 𝐨𝐟 𝐭𝐫𝐮𝐜𝐤𝐬 𝐫𝐞𝐪𝐮𝐢𝐫𝐞𝐝 = 𝟏𝟏; 𝐄𝐱𝐩𝐞𝐜𝐭𝐞𝐝 𝐩𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧 = 𝟐𝟏𝟐 𝐁𝐂𝐌/𝐡

Given the following information on a shovel/truck operation, calculate the expected production if two trucks are removed from the fleet. Shovel production at 100% efficiency = 283 BCM/h Job efficiency = 0.75 Truck capacity = 15.3 BCM Truck cycle time, excluding loading = 0.5 h

𝟏𝟖𝟔 𝐁𝐂𝐌/𝐡

24.1 km of gravel road require reshaping and leveling. You estimate that six passes of a motor grader will be required. Based on operator skill, machine characteristics, and job conditions, you estimate two passes at 6.4 km/h, two passes at 8.0 km/h, and two passes at 9.7 km/h. If job efficiency is 0.80, how many grader hours will be required for this job?

𝟐𝟑.𝟏 𝐡

Trial blasting indicates that a rectangular pattern of drilling using 7.6-cm holes spaced on 2.75-m centers and 6.1 m deep will produce a satisfactory rock break with a particular explosive loading. The effective hole depth resulting from the blast is 5.5 m. Determine the rock volume produced per meter of drilling.

𝟔.𝟖 𝐦³/𝐦

A jaw crusher is producing 227 t/h of crushed gravel and discharging it onto a three-screen deck. The top screen in the deck is a 38-mm screen. The gradation of crusher output shows 100% passing 76 mm, 92% passing 38 mm, and 80% passing 19 mm. Material weight is 1842 kg/m3. Find the minimum size of the 38-mm screen to be used. Check both total screen load and screen passing capacity. Hint: Basic capacity: Total feed = 62/t/h/m2 Passing screen = 34 t/h/m2 Deck position factor (top) = 1.0 Halfsize factor (80%) = 1.8 Oversize factor (8%): Total feed = 0.96 Passing screen = 1.04 Weight factor = 1.15

𝟐.𝟗 𝐦²

Calculate the maximum hourly production of an asphalt plant based on the data in the following list. Mix composition: Asphalt = 6% Aggregate composition: Coarse A = 42% Coarse B = 35% Sand = 18% Mineral filler = 5% Aggregate moisture = 8% Dryer capacity at 8% moisture removal = 110 ton/h Hint: Plant capacity = [Dry capacity × 10^4]/[(100 - asphalt%)(100 - fines%)]

𝟏𝟐𝟑 𝐭𝐨𝐧/𝐡

[NOV 2022] Calculate the volume of plastic concrete that will be produced by the mix design given in the table.

𝟎.𝟓𝟏 𝐦³

Determine the actual weight of each component to be added if the sand contains 5% excess moisture and the gravel contains 2% excess moisture.

𝐖𝐚𝐭𝐞𝐫 = 𝟔𝟑 𝐤𝐠; 𝐒𝐚𝐧𝐝 = 𝟒𝟒𝟕 𝐤𝐠; 𝐆𝐫𝐚𝐯𝐞𝐥 = 𝟓𝟔𝟎 𝐤𝐠

Refer to the previous problem. Determine the weight of each component required to make a three-bag mix and the mix volume.

𝐂𝐞𝐦𝐞𝐧𝐭 = 𝟏𝟐𝟕.𝟖 𝐤𝐠; 𝐒𝐚𝐧𝐝 = 𝟑𝟕𝟎 𝐤𝐠; 𝐆𝐫𝐚𝐯𝐞𝐥 = 𝟒𝟔𝟒 𝐤𝐠; 𝐖𝐚𝐭𝐞𝐫 = 𝟓𝟐 𝐤𝐠; 𝐌𝐢𝐱 𝐯𝐨𝐥𝐮𝐦𝐞 = 𝟎.𝟒𝟐 𝐦𝟑