A tri-axial test is conducted on a sand sample. The normal and shearing stresses on failure plane are 475 kPa and 350 kPa, respectively.
1. Determine the angle of shearing resistance.
A. 32.3°
B. 59.1°
C. 61.2°
D. 63.2°
2. Determine the angle that the failure plane makes with the horizontal.
A. 57.3°
B. 59.1°
C. 61.2°
D. 63.2°
3. What is the plunger stress in kPa?
A. 632.4
B. 869.5
C. 798.3
D. 812.7
Solution:
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A vertical tank having a horizontal cross-sectional area of 0.4 square meter has 0.0003m2 orifice at its bottom. The initial head on the orifice is h1 = 1.2m. It takes 312 second for the water level to drop from 1.2m to 0.6m.
1. What is the coefficient of discharge?
A. 0.65
B. 0.62
C. 0.68
D. 0.72
2. If C = 0.6, how long will it take for the water level to drop from 1.2m to 0.8m?
A. 202 s
B. 256 s
C. 185 s
D. 231 s
3. If C = 0.6, what is the head on the orifice after 240?
A. 0.52 m
B. 0.43 m
C. 0.85 m
D. 0.73 m
Solution:
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Water flows at the rate of 0.8 m3/s in a 900-m long pipe with a total head lost of 4m. Solve for the pipe diameter in mm by:
1. Darcy-Weisbach formula using f = 0.018.
A. 735
B. 715
C. 812
D. 793
2. Manning’s formula using n = 0.014.
A. 812
B. 735
C. 715
D. 793
3. Hazen-William’s formula using C1 = 130.
A. 812
B. 793
C. 735
D. 715
Solution:
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The elasticity and dimensions of a pipe leading from a reservoir are such that the celerity of pressure wave is 975m/s. The pipe has a length of 610m and a diameter of 1.2m. The flow is initially 0.85 m3/s.
1. What is the water hammer pressure for instantaneous valve closure?
A. 612.52 kPa
B. 731.25 kPa
C. 610.36 kPa
D. 680.74 kPa
2. What is the approximate water hammer pressure at the valve if it is closure in 4 s?
A. 188.8 kPa
B. 209.5 kPa
C. 212.1 kPa
D. 225.3 kPa
3. What pressure is expected when the discharge drops almost instantly from 0.85 m3/s to 0.28 m3/s?
A. 462.8 kPa
B. 550.5 kPa
C. 487.5 kPa
D. 510.2 kPa
Solution:
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A piece of metal weighs 250 N in air and 240 N in water.
1. Determine the volume of the piece of metal in cubic meter.
A. 0.0112
B. 0.0125
C. 0.0136
D. 0.0187
2. What is the unit weight of the metal in kN/m3?
A. 28
B. 25.74
C. 18.72
D. 31.22
3. What is the specific gravity of the metal?
A. 2.85
B. 2.62
C. 3.18
D. 1.91
Solution:
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A sheet pile 10.5 m in length is to retain a 7.3 m deep of soil with friction angle of 31°and unit weight of 17.5kN/m3. It is anchored to a depth of 1.2m below the top of the pile. The anchors are spaced 3m.
1. Find the total active force on the wall per meter width.
A. 279.9 kN
B. 308.8 kN
C. 358.4 kN
D. 421.2 kN
2. What percentage of the total passive resistance is utilized by the wall?
A. 77.7%
B. 65.3%
C. 95.5%
D. 84.5%
3. Determine the tension on the anchor.
A. 321.4 kN
B. 187.5 kN
C. 273.8 kN
D. 91.3 kN
Solution:
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Two footings rest in a layer of sand 2.7m thick. The bottoms of the footings are 0.90m below the ground surface. Beneath the sand layer is a 1.8m thick clay layer. Underneath the clay layer is solid surface. Beneath the sand layer is at a depth of 1.8m below the ground surface.
1. Compute the stress increase in kPa below footing A (1.5m x 1.5m) at the center of the clay layer. Assume that the settlement in the clay layer is the same beneath footings A and B.
A. 28.32
B. 20.14
C. 25.87
D. 22.68
2. Determine the size of footing B so that the settlement in the clay layer is the same beneath footings A and B.
A. 3.2m x 3.2m
B. 2.4m x 2.4m
C. 3.6m x 3.6m
D. 3.8m x 3.8m
3. Determine the settlement in mm beneath footing A.
A. 42.3mm
B. 34.2mm
C. 69.8mm
D. 57.4mm
Solution:
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A pre-stressed concrete pile, 300mm x 300 mm in cross-section, is to be driven in a clayey soil (γ = 18.5 kN/m3) as shown. The design pile has a design capacity of 450 kN. Use factor of safety of 2. The unconfined compression shear strength, qu, of the soil is 110 kPa. Use Nc = 9.
1. What is the end bearing capacity of pile in kN.
A. 44.6
B. 58.6
C. 62.7
D. 75.4
2. Compute the skin friction in kN expected to develop along the shaft of the pile.
A. 855.5
B. 963.2
C. 754.2
D. 689.1
3. Compute the length of the pile if frictional constant α = 0.6.
A. 14.5 m
B. 28.4 m
C. 21.6 m
D. 18.5 m
Solution:
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A 5-m thick sand layer overlies a very thick layer of clay. The sand has void ratio of 0.52 and specific gravity of solids of 2.62. The clay has moisture content of 42% and specific gravity of solids of 2.65. The water table is 3m below the sand (ground) surface. The sand above water table is 30% saturated.
1. Find the total active force on the wall per meter width.
A. 16.85 kN/m3
B. 18.21 kN/m3
C. 17.47 kN/m3
D. 17.04 kN/m3
2. Determine the total stress 10m below the ground surface.
A. 214.5 kPa
B. 154.8 kPa
C. 181.6 kPa
D. 112.9 kPa
3. Determine the effective stress 10m below the ground surface.
A. 112.9 kPa
B. 181.6 kPa
C. 154.8 kPa
D. 214.5 kPa
Solution:
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Water flows at the rate of 2m/s in a 2.5-km long 600-mm pipe that is 20mm thick. Bulk modulus of elasticity of water, EB = 2.2 x 109 Pa. Modulus of elasticity of pipe material is E = 1.4 x 1011 Pa. Density of water is 998 kg/m3.
1. Calculate the nearest value to the velocity of pressure (sound) wave in m/s.
A. 1087
B. 975
C. 1563
D. 1224
2. If a valve at the end of the pipe is closed, determine the maximum time of closure that can be considered as instantaneous closure.
A. 2.1 s
B. 4.1 s
C. 3.2 s
D. 5.2 s
3. Calculate the rise in pressure near the valve due to instantaneous closure of the valve.
A. 2145 kPa
B. 3254 kPa
C. 2443 kPa
D. 2864 kPa
Solution:
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The solid steel ball shown is submerged between the interface of two liquids. The ball has a diameter of 225mm and specific gravity of 7.4.
1. Determine the weight of the ball in Newtons.
A. 485
B. 433
C. 402
D. 387
2. Determine the buoyant force acting on the ball in Newtons.
A. 44
B. 87
C. 79
D. 35
3. Determine the tension in the rope in Newtons.
A. 354
B. 398
C. 315
D. 371
Solution:
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The tank shown is 3m wide into the paper. Neglect atmospheric pressure. Unit weight of water is 9.79 kN.m3.
1. Determine the nearest value to the vertical component of the total hydrostatic force on the quarter-circle panel AB, in kilo Newton.
A. 1485
B. 1365
C. 1658
D. 1505
2. Determine the nearest value to the resultant hydrostatic force acting on the quarter-circle panel AB, in kilo Newton.
A. 1164
B. 955
C. 1234
D. 1321
3. Calculate the nearest value to the angle that the resultant hydrostatic force makes with the horizontal, in degrees.
A. 39.7
B. 56.3
C. 48.1
D. 50.6
Solution:
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Water flow at the rate of 1.2 m3/s at a depth of 1.5m in a 10-m wide irrigation canal. Assume uniform flow and use n = 0.035.
1. Calculate the nearest value to the specific energy in Joule/Newton.
A. 1.5124
B. 1.5087
C. 1.5003
D. 1.5024
2. Determine the slope of the channel bed in meter per kilometer.
A. 0.0064785
B. 0.000064785
C. 0.0000064785
D. 0.064785
3. Determine the boundary shearing stress at the walls in Pa.
A. 0.00733
B. 0.0733
C. 0.0007333
D. 0.733
Solution:
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The following data were obtained from a tri-axial test on a cohesive soil:
Maximum shearing stress at failure plane = 65 kPa
Angle of friction = 28°
Cohesion = 31 kPa
1. Determine the plunger (deviator) stress in kPa.
A. 196.32
B. 214.57
C. 187.63
D. 147.23
2. Determine the minimum normal stress (confining pressure), in kPa.
A. 32.14
B. 18.54
C. 24.89
D. 85.42
3. Determine the normal stress on the plane of maximum shear, in kPa.
A. 98.51
B. 59.36
C. 68.47
D. 85.42
Solution:
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The velocity at which the change from laminar to turbulent flow occurs is:
a) lower than that from turbulent to laminar
b) equal to that from turbulent to laminar
c) higher than that from turbulent to laminar
d) none of these
Answer:
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A large cylindrical steel tank 4m. high with its bottom on level ground contains two layers of liquid. The bottom layer is water 2m. deep. The top layer is occupied by a liquid whose specific gravity is not known to a depth of 1m. A 50 mm diam. orifice with a coefficient of velocity of 0.98 is situated one meter from the bottom of the tank. The jet from the orifice hits the ground 2.75m horizontally away from the vena contracta. Determine the sp.gr. of the liquid.
Solution:
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Which of the following statements is not in accordance with Pascal’s Law?
a) The pressure is the same in all directions at any point in a fluid at rest.
b) The pressure applied at any point to a liquid in a closed vessel is transmitted undiminished to every portion of the vessel
c) A body submerged in a fluid apparently weighs less by an amount equal to the weighs less by an amount equal to the weight of fluid displaced.
d) None of these
Answer:
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Horizontal orifice under a constant head of 1.30m. issues a jet which hits a point 5m. below the centerline of the orifice and 5m horizontally from the vena contrata. What is the coeff. of velocity?
Solution:
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What is the discharge capacity of a concrete pipe culvert 4 ft. in diam. And 10m. long if the difference in water level at the outlet is 10m. Assume coefficient of discharge C = 0.74.
Solution:
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A watershade covering an area consisting of an equilateral triangle ABC and a square section on the side BC. AV is 1.5km. long. If the storm precipitation depths as measured on the rain gages at A, B and C are 75 mm., 125 mm and 100 mm respectively, compute the average precipitation over the watershed using Thiessen’s polygon method.
Solution:
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If the discharge over a 45° triangular weir is 0.021 m3/sec. What is the head if C = 0.594?
Solution:
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A vertical jet of water thru a nozzle supports a load of 150 N. The velocity and diameter of the jet at the nozzle tip are 17.46 m/s and 3 cm. Find the distance of load from the nozzle tip in meters.
Solution:
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On slow filter, thin gelatinous surface coat of biological growth maybe develop.
a) facultative
b) biomass
c) sludge bulking
d) Shmuthdecke
Answer:
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Type of bacteria found in water which lives and developed without oxygen.
a) facultative
b) Bacilli
c) sponge
d) anaerobic
Answer:
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Wastewater from a residential community is 400 liters per person per day containing 200 milligram per liter BOD and 240 milligram per liter suspended solids. Determine the number of grams of BOD per person per day.
Solution:
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A nozzle situated at ground level issues a jet inclined at 30° with a velocity of 12 m/s. How long will it take before the jet hit the ground?
Solution:
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Find the discharge through a rectangular suppressed weir in m3/sec if L = 2.4m. and H = 18cm. Neglect velocity of approach. Use Francis formula.
Solution:
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Assuming the same cross sectional area and slope, which of the following channel shapes will give the highest discharge?
Solution:
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Wastewater from residential community is 400 liters per person per day containing 240 mg/liter suspended solids. Calculate the number of grams of suspended solids per person per day.
Solution:
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A drainage canal in the shape of trapezoid with a bottom width of 2.5m. and sideslope of 1 hor. To 1.5 vertical carries water at a depth of 3m. Find the discharge in m3/sec using Mannings formula. S = 0.0004, n = 0.015.
Solution:
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A spillway 12.9m. long releases flood run off from a reservoir 5 hectares in area. If the reservoir level drops from elevation 55m to 54m. in 2520 sec. fond the elevation of the crest of the spillway in meters. Use Francis formula. Assume constant reservoir surface area.
Solution:
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A storm drain with a radius of 1.8 m. flows half full. Find the hydraulic radius in meters.
Solution:
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If a 5kg steel plate attached to an end of a 0.1 x 0.3 x 1.2m. wooded pole, what is the length of the pole above the water? Use sp.gr. of wood equal to 0.50. Neglect buoyant force on steel.
Solution:
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A dam 4m. on top, 10m at the bottom and 20m. high has water 15m. depth acting on its vertical side. What is the factor of safety against sliding if the coefficient of friction is 0.80.
Solution:
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Water flows in a rectangular canal having a width of 1m. and a depth of 0.6m. at the rate of 0.07 m3/sec. Determine the type of flow.
Solution:
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