MSTE

Question 1

Find the swell of a soil that weighs 2800 lb/cu yd (1661 kg/m’) in its natural state and 2000 lb/cu yd (1186 kg/m*) after excavation.

Answer 1

40%

Question 2

Find the shrinkage of a soil that weighs 2800 lb/cu yd (1661 kg/m’) in its natural state and 3500 lb/cu yd (2077 kg/m’) after compaction.

Answer 2

20%

Question 3

(MAY 2018, NOV 2018) A soil weighs 1960 /BCM), and 3500 lb/CCY (2077 kg/CCM). (a) Find the load factor and shrinkage fact for the soil. (b) How many bank cubic var (BCY) or meters (BCM) and compacted cubic yards (CCY) or meters (CCM) are contained in 1 million loose cubic yards (593,300 LCM) of this soil?

Answer 3

(a) Load Factor = 0.70, Shrinkage Factor = 0.80 (b) Bank Volume = 700,000 BCY or 415,310 BCM, Compacted Volume = 560,000 BCY or 332,248 BCM

Question 4

(MAY 2019) Find the base width and height of a triangular spoil bank containing 100 BCY (76.5 BCM) if the pile length is 30 ft (9.14 m), the soil’s angle of repose is 37°, and its swell is 25%.

Answer 4

B = 7.45 m, H = 2.80 m

Question 5

Find the base diameter and height of a conical spoil pile that will contain 100 BCY (76.5 BCM) of excavation if the soil’s angle of repose is 32° and its swell is 12%.

Answer 5

D = 10.16 m. H = 3.17 m

Question 6

Estimate the volume of excavation required (bank measure) for the basement shown in Figure 3. Values shown at each corner are depths of excavation. All values are in feet (m).

Answer 6

146.6 BCM

Question 7

Find the volume (bank measure) of excavation required for a trench 3 ft (0.92 m) wide, 6 ft (1.83 m) deep, and 500 ft (152 m) long. Assume that the trench sides will be approximately vertical.

Answer 7

255 BCM

Question 8

Find the volume of excavation required for the area shown in Figure 4. The figure at each grid intersection represents the depth of cut at that location. Depths in parentheses represent meters.

Answer 8

14,596 BCM

Question 9

(MAY 2022) Estimate the actual bucket load in bank cubic yards for a loader bucket whose heaped capacity is 5 cu yd (3.82 m3). The soil’s bucket fill factor is 0.90 and its load factor is 0.80.

Answer 9

2.75 BCM

Question 10

(APR 2024, NOV 2023, MAY 2022, NOV 2021) Find the expected production in loose cubic yards (LCM) per hour of a small hydraulic excavator. Heaped bucket capacity is 3/4 cu yd (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 14 ft (4.3 m). Maximum depth of cut is 20 ft (6.1 m) and average swing is 90.

Answer 10

113 LCM/h

Question 11

Find the expected production in loose cubic yards (LCM) per hour of a 3-yd (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.

Answer 11

290 LCM/h

Question 12

Determine the expected dragline production in loose cubic yards (LCM) per hour based on the following information: Dragline size = 2 cu yd (1.53 m3) Swing angle = 120° Average depth of cut = 7.9 ft (2.4 m) Material = common earth Job efficiency = 50 min/h Soil swell op = 25%.

Answer 12

165 LCM/h

Question 13

Estimate the production in loose cubic yards per hour for a medium-weight clamshell excavating loose earth. Heaped bucket capacity is 1 cu yd (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.

Answer 13

53 LCM/h

Question 14

(NOV 2022, NOV 2019) A wheel tractor-scraper weighing 100 tons (91 t) is being operated on a haul road with a tire penetration of 2 in. (5 cm). What is the total resistance (Ib and kg) and effective grade when the scraper is ascending a slope of 5%; the scraper is descending a slope of 5%?

Answer 14

9,100 kg, 10%

Question 15

(NOV 2022) A wheel tractor-scraper weighing 100 tons (91 t) is being operated on a haul road with a tire penetration of 2 in. (5 cm). What is the total resistance (Ib and kg) and effective grade when the scraper is descending a slope of 5%?

Answer 15

0 kg, 0%

Question 16

(MAY 2022) A crawler tractor weighing 80,000 lb (36 t) is towing a rubber-tired scraper weighing 100,000 lb (45.5 t) up a grade of 4%. What is the total resistance (Ib and kg) of the combination if the rolling resistance factor is 100 lb/ton (50 kg/t)?

Answer 16

5,535 kg

Question 17

(APR 2023, MAY 2022) A power-shift crawler tractor has a rated blade capacity of 10 LCY (7.65 LCM). The dozer is excavating loose common earth and pushing it a distance of 200 ft (61 m). Maximum reverse speed in

Question 18

third range is 5 mi/h (8 km/h). Estimate the production of the dozer if job efficiency is 50 min/h.

Answer 18

271 LCM/h

Question 19

Estimate the hourly production in loose volume (LCY and LCM) of a 31/2-yd (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 200 ft (61 m), the effective grade is 6%, the bucket fill factor is 1.00, and job efficiency is 50 min/h.

Answer 19

168 Lm’/h (Actual Board: 178 Lm’/h)

Question 20

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.

Answer 20

2 and 3

Question 21

Find the expected production of the scraper fleet of Example 10 if only one pusher is available and the chain-loading method is used. Expected production of a single scraper assuming adequate pusher support is 226 BCY/h (173 BCM/h).

Answer 21

1,112 BCM/h

Question 22

Given the following information on a shovel/truck operation, (a) calculate the number of trucks theoretically required and the production of this combination; (b) calculate the expected production if two trucks are removed from the fleet.

Answer 22

(a) Il trucks and 212 BCM/h (b) 186 BCM/h

Question 23

Fifteen miles (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 4 mi/h (6.4 km/h), two passes at 5 mi/h (8.0 km/h), and two passes at 6 mi/h (9.7 km/h). If job efficiency is 0.80, how many grader hours will be required for this job?

Answer 23

23.1 h

Question 24

Trial blasting indicates that a rectangular pattern of drilling using 3-in. (7.6-cm) holes spaced on 9-ft (2.75-m) centers and 20 ft (6.1 m) deep will produce a satisfactory rock break with a particular explosive loading. The effective hole depth resulting from the blast is 18 ft (5.5 m). Determine the rock volume produced per foot (meter) of drilling.

Answer 24

6.8 m’/m

Question 25

Estimate the hourly production and the unit cost of rock excavation by ripping for the problem of Example 28. Field tests indicate that a D7G dozer with ripper can obtain satisfactory rock fracturing to a depth of 27 in. (0.686 m) with two passes of a single ripper shank at 3-ft (0.914-m) intervals. Average speed, including turns, is estimated at 82 ft/min (25 m/min).

Answer 25

392 BCM/h and 0.242/BCM

Question 26

A jaw crusher is producing 250 tons/h (227 t/h) of crushed gravel and discharging it onto a three-screen deck. The top screen in the deck is a 1V/ 2 in. (38-mm) screen. The gradation of crusher output shows 100% passing 3 in. (76 mm), 92% passing 11/2 in. (38 mm), and 80% passing 3/2 in. (19 mm). Material weight is 115 lb/cu ft (1842 kg/m3). Find the minimum size of the 11/2 in. (38-mm) screen to be used. Check both total screen load and screen passing capacity.

Answer 26

2.9 m₴

Question 27

(NOV 2022) Calculate the volume of plastic concrete that will be produced by the mix design given in the table: Quantity Component Cement Sand (SSD) Gravel (SSD) Water Specific Gravity 3.15 2.65 2.86 1.00 340 940 1210 210 kg 154 426 549 95

Answer 27

0.51 m

Question 28

Determine the actual weight of each component to be added if the sand contains 5% excess moisture and the gravel contains 2% excess moisture. Quantity Component Cement Sand (SSD) Gravel (SSD) Water Specific Gravity 3.15 2.65 2.66 1.00 340 940 1210 210 kg 154 426 549 95

Answer 28

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

Question 29

Determine the weight of each component required to make a three-bag mix and the mix volume. Component Cement Sand (SSD) Gravel (SSD) Water Specific Gravity 3.15 2.65 2.66 1.00 340 940 1210 210 Quantity kg 154 426 549 95

Answer 29

Cement = 127.8 kg, Sand = 370 kg Gravel = 464 kg, Water = 52 kg, Mix Vol. = 0.42 m3

Question 30

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

Answer 30

123 ton/h

Question 31

Determine the rated size of air compressor required to operate the following tools at an altitude of 6000 ft (1830 m). Assume a 10% leakage loss and a job load factor of 0.80. Rated Consumption Item Drifter drills Hand-held drills Trench diggers Tampons Submersible pumps cu ft/min numbar 215 6.1 80 2.5 30 40 0.8 1.1 90 2.3

Question 32

Determine the safe load capacity of a 6-in.-square concrete pile 60 ft long. Assume that the unit weight of the pile is 150 Ib/cu ft. Pile driver energy = 14,000 gt-lb Ram weight = 4000 lb Weight of driving appurtenances = 1000 lb Average penetration last six blows = 1/5 in./blow

Answer 32

49.1 m'/min

Question 33

Calculate the safe load capacity of a bulb pile based on the following driving data. Hammer weight = 3 tons Height of drop = 20 ft Volume in last batch driven = 5 cu ft Number of blows to drive last batch = 40 Volume of base and plug = 25 cu ft Selected K value = 25

Answer 33

59,862 lb

Question 34

Determine the design lateral force for the slab form 6 in. (152 mm) thick, 20 ft (6.1 m) wide, and 100 ft (30.5 m) long shown in Figure 5. The slab is to be poured in one pour. Assume concrete density is 150 1b/cu ft (2403 kg/m') and that the formwork weighs 15 lb/sq ft (0.72 kPa).

Answer 34

1.46 kN/m

Question 35

Calculate the number of bricks 33/4 × 21/4 x 8 in. (95 × 57 × 203 mm) laid in running bond required for a double wythe wall 8-ft high by 14-ft wide (2.44 x 4.27 m) having one opening 48 x 72 in. (1.22 × 1.83 m) and one opening 32 x 48 in. (0.81 × 1.22 m). Mortar joints are 1/2 in. (13 mm). Allow 3% for brick waste.

Answer 35

981

Question 36

Estimate the quantity of mortar required for the problem of Example 1. The joint thickness between wythes is 1/2 in. (13 mm). Assume a 25% waste factor.

Answer 36

0.53 m

Question 37

Using the straight-line method of depreciation, find the annual depreciation and book value at the end of each year for a track loader having an initial cost of $50,000, a salvage value of $5000, and an expected life of 5 years.

Answer 37

$ 9,000

Question 38

Estimate the hourly repair cost for the first year of operation of a crawler tractor costing $136,000 and having a 5-year life. Assume average operating conditions and 2000 h of operation during the year.

Answer 38

$ 4.08

Question 39

A copper wire has a nominal breaking strength of 300 MPa and a reduction of area of 77 %. Calculate the true tensile strength.

Answer 39

1,300 MPa

Question 40

A 2-in (5.08 cm) gage length is marked on a copper rod. The rod is strained so that the gage marks are 2.27 in. (5.77 cm). Calculate the strain.

Answer 40

13.5%

Question 41

If the average modulus of elasticity of the steel used is 205,000 MPa, how much will a wire 2.5 mm in diameter and 3 meters long be formed when it supports a load of 500 kg?

Answer 41

1.5 cm

Question 42

A copper wire has a nominal breaking strength of 300 MPa and a reduction of area of 77 %. Calculate the true strain at the point of fracture.

Answer 42

147%

Question 43

An aluminum wire is stressed 34.5 MPa in tension. What temperature increase is required to change its length by the same amount?

Answer 43

22°C

Question 44

A stainless steel plate 0.4 cm thick has circulating hot water on one side and a rapid flow of air on the other side, so that the two metal surfaces are 90°C and 20°C, respectively. How many joules are conducted through the plate per minute?

Answer 44

1,575 J/cm? min

Question 45

The true density of a concrete to which an air-entraining agent was added is 2.80 g/cm3. However, a dry core (15.24 cm x 10.16 cm in diameter) of this concrete weighs only 2.982 kg. The same core weighs 3.08 kg when saturated with water. What are the percents of the open and closed pores?

Answer 45

7.9% and 5.9%

Question 46

The true density of a concrete to which an air-entraining agent was added is 2.80 g/cm3. However, a dry core (15.24 cm x 10.16 cm in diameter) of this concrete weighs only 2.982 kg. The same core weighs 3.08 kg when saturated with water. What are the bulk and apparent densities?

Answer 46

2.41 and 2.62

Question 47

A concrete unit mix contains 136 kg of gravel, 95 kg of sand, 42.5 kg of Portland cement, and 22.5 kg of water, plus 5% entrained air. How much cement is required to build a low retaining wall, 28.6 m by 1.07 m by 0.305 m? (The aggregate is non porous)

Answer 47

71.5 unit mixes

Question 48

An electrical porcelain has only 1% porosity as sold. It had 27% porosity after pressing and drying, but before sintering. How much linear shrinkage occurred during sintering?

Answer 48

9.7%

Question 49

To compress 2.8 m' of free air per minute from atmospheric (0.101 N/mm?) to (0.7 N/mm?) indicated on the gauge (i.e. 8.01 bar absolute).

Answer 49

9.7 kW or 13.1 HP

Question 50

To compress 2.8 m' of free air per minute from 0.05 N/mm? (atmospheric pressure) to 0.801 N/mm? (absolute pressure) requires a compressor with a power value of?

Answer 50

6.47 kW

Question 51

Determine the hourly production of a 0.57 m capacity backhoe, excavating a foundation 3 m deep in common earth.

Answer 51

N/A