CIVIL ENGINEERING Mock ExaminationMAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING 1. A cohesive soil deposit is considered soft if the unconfined compression strength, in kPa, is between A. 0 to 24 C. 96 to 192 B. 48 to 96 D. 24 to 48 2. A fireman has to put out a fire but is blocked by a fire wall. To reach over the wall, he directed the water jet from the nozzle at an angle of 30 deg to the horizontal. Evaluate the velocity of the water, in meters/sec, leaving the nozzle of his hose to reach over the wall if he stands 30 meters away from the wall and the wall is standing 2 m higher than the nozzle of the hose. Neglect friction in the jet. A. 16.8 C. 18.2 B. 20.6 D. 19.6 3. A line joining the points of highest elevation of water in a series of vertical open pipes rising from a pipeline in which water flows under pressure is referred to as A. hydraulic loss C. hydraulic jump B. hydraulic gradient D. hydraulic head 4. In a triaxial shear test of a cohesionless soil, the soil cylinder was subjected to a liquid pressure of 16 kPa inside the chamber. It was observed that failure of the sample in shear occurred when the axial compressive stress reached 40 kPa. The angle of internal friction in degrees is nearest to A. 27.4 C. 26.8 B. 29.1 D. 25.4 5. A barge, weighing 350 kN when empty, is 6 m wide, 15 m long, and 3 m high. Floating upright, evaluate the draft of the barge, in meters, when transporting 3000 bags of cement along a river, each bag having a mass of 40 kg. Assume the specific gravity of the water in the river to be 1.02. A. 1.38 C. 2.01 B. 2.57 D. 1.67 6. A spherical balloon 6 m in diameter is filled with gas weighing 5 N/m-3. In standard air weighing 12 N/m-3, evaluate the maximum load, in N, excluding its own weight, that the balloon can lift. A. 812 C. 672 B. 792 D. 916 7. Determine the pressure in a vessel of mercury at a point 200 mm below the liquid surface, expressing the answer in kPa absolute. A. 132 C. 134 B. 130 D. 128 8. Water flows through a rectangular irrigation canal, 500 mm deep by 1 m wide, with a mean velocity of 2 meters per second. Determine the rate of flow in m^3 per minute. A. 50 C. 80 B. 70 D. 60 Page 1 of 8 9. 8. potential head C. Obtain the draft. A soil sample has a water content of 20 percent and moist unit weight of 18 kN/m^3. B. 0. 0. The hydraulic head in the 10-mm diameter standpipe through which test water passed dropped from 900 to 600 mm in one-minute of observation. 1. The failure load was recorded at 240 N. 0.00541 D. Evaluate the coefficient of permeability of the soil sample. The ship captain recorded a draft of 8.0 D. 3. 0. 0.00715 B. 1. An unconfined compression test was conducted on a sample of clay having a diameter of 50 mm.4 m while the ship was still in seawater (specific gravity = 1.44 C. hydrodynamics 12.50 C.75 C. A. For the tank shown in FIGURE HHP-1. 3. 1.28 16. 660 13. Evaluate the resisting capacity against axial load due to skin friction Size of pile: 0. of the ship in fresh water if the horizontal section of the ship below the waterline is 3000 m2 in both instances. A pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly (momentum change) is referred to in hydraulics as A.0 Page 2 of 8 .368 15.59 11. in meter(s).37 B. 3.19 D. in kPa. of the oil if its specific gravity is 0. water hammer B. 0. 1320 D. in meters.733 B.1 B. 61. A. hydraulic jump D.CIVIL ENGINEERING Mock Examination MAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING 9.03). A. A. obtain the depth d.00924 C. A layer of soft clay having an initial void ratio of 2.407 C. is nearest to a value of A.33 B.635 D. In that duration the water collected in the graduate was recorded at 1. Obtain the void ratio of the soil.54 B. in meters.84.65.15 10.00689 14. in cm/sec. A ship having a displacement of 20.000 metric tons enters a harbor of fresh water. Under a compressive load applied above it.5 liters. 101. 0. 3. The cohesion strength of the clay. 64. A. 8.78 D. 0. the void ratio decreased by one-half. 1.0 C.30 m square Depth of penetration into the Unconfined compression strnegth A. 1010 C.00 is 10 m thick. 7. The specific gravity of the solids is 2. The permeameter in a falling head permeability test setup involves a cylindrical soil sample 50 mm in diameter and a height 200 mm. 45. Evaluate the reduction in the thickness of the clay layer.74 D. Evaluate the reduction in the thickness of the clay layer. 11.2 22. A. in kPa.50 20. continuous B.00412 B. the flow is called A. the void ratio decreased by one-half. If the velocity head at one point of a pipeline is 5 m. A.015. 15 B. 3. there are 8 potential drops. at the point of the pipeline if the velocity is increased three times? A. Evaluate the seepage flow per meter width of dam.2 m. laminar D. the flow is 30 m^3/sec. Under a compressive load applied above it.CIVIL ENGINEERING Mock Examination MAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING 17. When the path lines of the individual particles of a flowing liquid are irregular curves and continually cross each other and form a complicated network.5 B. in meters. a distance of 30 meters. 181 D. 19. 0. A layer of soft clay having an initial void ratio of 1. 114 23.6 Situation 2 – According to the elastic theory. the vertical stress induced by flexible line load of infinite length that has an intensity of q units/length on the surface of a semi-infinite soil mass can be estimated by the expression p = 0. uniform C.6 B. 0. 5.00447 19.00 B. 4. 17. 177 B. 22.6 C. 14. Determine the uplift pressure at the heel of the dam.25 C. A.50 is 10 m thick. 45 D. When the depth of the flow is 1. what would be the velocity head.4 C.00316 D. 3. The base of the dam is founded 1 m below the ground. 30 SITUATIONAL Situation 1 – The coefficient of permeability below a dam is 4 m/day.7 D. in kPa.75 D. in liters/min. 21. Nd=10 and the number of flow channels Nf=4. Determine the uplift pressure at the toe of the dam. Evaluate the slope of the channel using Mannings formula. A. The roughness coefficient n = 0.6 D. 20.637 q/N when N = z[1+(r/z)2]2 Page 3 of 8 . 32. turbulent 18. A trapezoidal canal has a bottom width of 4 m and side slopes of 2 horizontal to 1 vertical. 20 C. To estimate the seepage below the dam. Between the heel and the toe of the dam. The water on the upstream side is 20 meter higher than on the downstream side. 0. 0. 198 C.00195 C. 18. A. a flow net was graphically drawn such that the number of potential drops. 4. A.668 B. Evaluate the stress at a depth of 2 m and a horizontal distance of 3 m from the line of the load. Evaluate the bearing pressure. the cohesion strength is 10 kPa. A. 7.000 inhabitants.2 m below the ground surface for which the bulk unit weight of the soil is 20 kN/m^3. 150 m.330 D. BC is 9150 m. The ground water table is at a level that does not affect the unit weight of the soil.531 D.450 C. in kPa.49 m with 25. pipe AB A. A. 10 B.205 D. 30. 15. 0.420 28. 260 D.150 Situation 4 – A square footing 4 m on a side is founded 1.CIVIL ENGINEERING Mock Examination MAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING r = horizontal distance from the line of the load z = depth of interest at which stress is induced A concrete hollow block wall weighing 6 kN per lineal meter is carried by a wall footing 0. Evaluate the stress in the soil caused by the load depth equal to twice its width. 247 C. evaluate the contribution of the following to the ultimate soil bearing capacity. B is the junction at Elev. 0. Under the condition of general shear failure. Length AB is 15. 16 25.25 C. C is a town at Elev. reservoir A is the source of water supply and is at Elev.500 D. Determine the size of the pipes if the consumption is 150 liters per capita per day. 0. 0.366 C.24 m with a population of 30.300 D.432 C. cohesion strength A. 0. 14 C. 185 Page 4 of 8 . 259 C. 24. For the pipes. 0.450 C. pipe AB C. 0.60 m wide. 0.47 D.02. 0.196 29. 6. 91. soil overburden A.302 Situation 3 – In FIGURE HTRS-2. 0. 179 B. pipe BC A. 12 D. 5. 0. 0.216 B.46 m.390 B. 235 D. 0.240 m. of 27. Use Terzaghi’s bearing capacity factors.31 26. 0. frictional factor f = 0. TABLE SMBC can be useful. 230 B. D is another town at Elev. 0. Determine the required diameter. and the angle of internal friction is 20 deg. exerted by the footing onto the supporting soil. BD is 6100 m.000. 30. 287 31. in kPa.43 B. in meters. 0. footing dimension A.355 35. Using Manning’s formula: V = (R^2/3)(S^1/2)/n.308 C. 1. 177 C. slope of the canal bed = 0. 2. in meter(s) A. A.82 B. Evaluate the percentage volume of the block that floats in the liquid. in kN. obtain the weight of the block.5 horizontal to 1 vertical. 1. 0.432 C. 0.652 B. 0. side slope = 1. Evaluate the total force acting on one side of gate. 67. 0. A.71 C. depth of water = 0.5 C. 143 D. 879 D. velocity of the water in m/sec.316 C.225 D. 3. A. 0. 74. 102 Situation 5 – A rectangular gate 1. 39. 82.3 D. 154 B.5 is placed in a container containing liquid having specific gravity of 13. 165 34. 0. 53. A.687 D. coefficient of roughness = 0.05 C. 0. If the volume of the block is 0.214 B. 0.05 Situation 7 – An irrigation canal with trapezoidal cross sections has the following dimensions: Bottom width = 2.90 m. 0. A.501 B.00 m.874 41.6. in meter(s) A.025. 0.824 C.3 38. 0. A.5 m wide and 3 m high is vertically submerged in water with its top edge horizontal and 2mbelow the water surface.98 B. 3. The canal will serve clay-loam Riceland for which the duty of water per hectare is 3. in kN. 98 C.001. Obtain the downward force in kN required to make it completely submerged in the liquid. 128 B. 3. number of hectares served by the irrigation canal. 0. 978 B. 36. A.96 D. 3. 0. 0. 0. 789 Page 5 of 8 .242 D.0 liters/sec.3 B. 0.479 D. Obtain the location of the force from the liquid surface.575 40. determine the hydraulic radius of the canal.751 37.020 cubic meter. Obtain the location of the force from the center of gravity of the plate. 897 C.22 D. in meters. 33.566 B. 3.CIVIL ENGINEERING Mock Examination MAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING 32. 116 D.61 Situation 6 – A solid block having a specific gravity of 3. 28 Situation 9 – A rectangular irrigation canal 6 m wide contains water 1. 18.7 B.67 B. 1.013.38 C. 2. 11. 1.56 43.3 m in diameter and 2.6 44.06 D. 1. 45.0 m deep. It has a hydraulic slope of 0.06 D. 2. 12. 2. Evaluate the discharge in the canal.87 C.5 B. 19. A. 20. 13. Evaluate the mean velocity of the water in the canal.26 C.35 B. 2. 2. 1. Determine the amount of water in liters that will be spilled out. using the more economical proportions but adhering to the same discharge and slope? A.91 D. 1. 1. 140 C.8 D. Obtain the unit weight of the sample in kN/m^3 when fully saturated. 2. in m^3/sec. 2. in m/sec.001 and a roughness coefficient of 0.52 C. 2. 2. so that no water is spilled out? A. A. 152 D. 1. 10. 2. What is the hydraulic gradient at hydraulic condition? A.44 C.1 m high is 2/3 full of water. 1.43 C.60.11 D. A.65 D. 2.38 46.52 Situation 10 – An open cylindrical vessel 1.77 B.35 49. Determine how high is the paraboloid formed of the water surface.55 D. 21. in meters. 42. in meters. 146 50. A.36 Page 6 of 8 .3 C. 1. A.46 B. 1. 2.8 C. 48. Evaluate the specific gravity of the soil solids. A.0 47. in meter(s).6 D. What should have been the least height of the vessel. If rotated about the vertical axis at a constant angular speed of 90 rpm. What would have been the depth of the canal. 341 B.01 B.15 B.CIVIL ENGINEERING Mock Examination MAY 2016 HYDRAULICS & GEOTECHNICAL ENGINEERING Situation 8 – A soil sample has a dry unit weight of 17 kN/m^3 and a void ratio of 0. 3. 1. 24 FIGURE HTRS-2 Page 7 of 8 . 30. 15.CIVIL ENGINEERING Mock Examination MAY 2016 d Oil Water 4 m 3 m Water FIGURE HHP-1 Elev.46 Town D Elev. 150 Town C Elev.49 A B Elev. 91. 37 4.10 1.8 3.55 23 21.22 0.44 3.00 0.00 0.06 6.2 22.06 2.10 6.7 7.57 16 13.10 0.36 0.30 1.2 20.98 0.74 1.2 6.81 0.04 4 6.38 0.59 0.92 1.0 16.12 21 18.15 2.19 5.2 15.88 19 15.4 11.34 1.10 7.73 1.42 14 12.51 4.7 4.32 2.96 2.92 4.36 3.31 12.22 1.30 12 10.9 4.30 1.67 17 14.08 14.CIVIL ENGINEERING Mock Examination MAY 2016 Table SMBC – Terzaghi’s Bearing Capacity Factors Φ General shear failure Local shear failure deg Nc Nq Nγ N’c N’q N’γ 0 5.04 8.06 5 7.1 12.00 0.61 2.56 8.74 1.48 1.00 1 6.30 6.00 0.47 3.02 1.52 9.20 6.13 8 8.69 0.29 0.74 24 23.03 20 17.90 1.5 19.30 0.88 1.14 0.18 10.85 3.05 2.1 18. the value of c is reduced by 1/3.97 1.35 7.14 5.9 11.76 30 37.6 5.21 0.8 13.00 0. Page 8 of 8 .64 0.44 0.13 0.62 1.66 3.22 0.55 0.03 7.07 0.34 14.02 1.47 1.17 1.39 qu = KccNc + KqγDfNq + KγγBNγ qu = ultimate bearing capacity γ = unit weight of the soil B = width of footing c = cohesion of soil Df = depth of founding of footing Nc Nq Nγ = bearing capacity factors q = overburden pressure Kc Kq Kγ = constants General shear failure Footing Kc Kq Kγ Long 1.60 2.6 6.70 1.64 11.9 8.76 18 15.35 13 11.07 6 7.2 2.45 1.39 0.10 7 8.20 1.26 9.53 6.07 3.70 3.27 7.84 15.30 1.29 29 34.1 14.45 2.64 1.69 8.01 2 6.6 16.09 2.88 28 31.49 0.24 11 10.49 0.00 1.90 3.31 2.30 For local shear failure.1 6.70 1.92 0.2 18.82 10.50 Square 1.70 0.00 13.6 17.60 2.97 25 25.16 9 9.99 8.80 5.2 9.02 3 3.31 4.94 0.7 17.8 10.7 8.00 0.35 22 20.25 26 27.4 3.04 2.85 8.1 4.26 4.07 11.48 15 12.09 12.14 6.00 5.30 1.40 Circular 1.44 7.01 5.20 10 9.82 0.04 6.82 1.00 1.22 0.73 0.4 7.54 2.67 2.63 2.59 10.08 0.61 1.51 1.97 1.3 9.35 0.59 27 29.