UNIVERSITY OF BOLTON RAK ACADEMIC CENTRE BENG (HONS) CIVIL ENGINEERING SEMESTER ONE EXAMINATION 2017/2018 GROUND AND WATER STUDIES 1

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1 OCD023 UNIVERSITY OF BOLTON RAK ACADEMIC CENTRE BENG (HONS) CIVIL ENGINEERING SEMESTER ONE EXAMINATION 2017/2018 GROUND AND WATER STUDIES 1 Date: Friday 12 th January 2018 INSTRUCTIONS TO CANDIDATES: MODULE NO: CIE4009 Time: 10.00am -1.00pm Answer SECTION A and SECTION B on separate answer books. There are THREE questions in Section A. (Answer ANY TWO). There are FOUR questions in Section B (Answer ANY THREE). All questions carry equal marks. Marks for parts of questions are shown in brackets. This examination paper carries a total of 100 marks. Formula sheet/supplementary information is provided at the end of each section. All working must be shown. A numerical solution to a question obtained by programming an electronic calculator will not be accepted.

2 Page 2 of 15 University of Bolton SECTION A Q1. Q2. (a) (b) (a) An Old tuberculated water main with moderate degree of attack in poor condition delivers 3025 litres/minute over a distance of 2.5km from a main reservoir to a service reservoir. If the water level in the service reservoir is 125 m below that of main reservoir, determine the pipeline diameter (HRS tables provided). (12 marks) A concrete-lined trapezoidal channel with bottom width of 3m and side slopes of 1vertical to 2 horizontal is designed to carry a flow of 85 m 3 /s. Determine the bed slope of the channel if the depth of water in the channel is 2.75m.Take Manning s coefficient for concrete as (8 marks) Total 20 marks Water flows from a storage tank through a 20 m horizontal pipeline of 200 mm diameter and a half closed gate valve (KL = 12) is present on the pipeline. The water level in the tank is 4m above from the centerline of the pipe and the entrance to pipe is sharp (KL = 0.5 for sharp entrance). Taking account of all energy losses, determine the flow rate in the pipeline if the other end of the pipeline is discharging to the atmosphere. Consider the Darcy friction coefficient of the pipe as (b) (13 marks) Explain the term energy head. Define the 3 components of Bernoulli s equation. (7 marks) Total 20 marks Please turn the page

3 Q3 (a) (b) Page 3 of 15 A wooden cylinder of length 5m and diameter 2.5m is floating on water with its longitudinal axis vertical. The density of wood is 650 kg/m 3. Calculate the metacentric height and comment on the stability of the tank by briefly explaining the significance of metacentric height in the stability of floating bodies. Use suitable diagrams and equations. (12 marks) A U-Tube manometer containing Mercury (ρ=13600kg/m 3 ) is used to measure the pressure of liquid in pipeline as shown in Figure Q3a. The pipeline fluid is having a specific gravity of 0.9 and if x = 0.25 and h = 0.75 m, find the pressure at Y. Figure Q3 a. Please turn the page for supplementary information for SECTION A (8 marks) Total 20 marks

4 Recommended Roughness values Page 4 of 15 Please turn the page for HRS Tables

5 Page 5 of 15 Please turn the page

6 Page 6 of 15 Please turn the page for formula sheet

7 Formula sheet P gh Q AV 2 P1 v1 z ρg 2g h f H L 2 Lv LQ 2gd 12.1d 1 2 v K L. 2g KL entry to pipe = 0.5 ; A Q n A R P I MB V R. S 2 o MG MB BG 2 P2 v 2 z ρg 2g hf hl Page 7 of 15 END OF SECTION A Please turn the page for Section B

8 Page 8 of 15 SECTION B Q4. Answer the questions below briefly. Use sketches where appropriate. (a) An engineer has proposed to construct a fill using a poorly-graded silty sand material, instead of a well-graded material composed mainly by sands and gravels. What would you say to this engineer regarding his decision? (3 marks) (b) Explain what special concern needs to be taken into account when designing ground anchors in a soil with a liquidity index greater than 0.2. (3 marks) (c) Explain why glacial deposits are expected to present a higher degree of consolidation than Aeolian deposits. (3 marks) (d) What is an alluvial terrace? How do these deposits form? Help your answer with a sketch. (4 marks) (e) Explain the difference in the values of the soil permeability for two samples of sand and clay. What are the ranges of permeability for each material? (3 marks) (f) A footing has been proposed to be constructed a 1.5m depth below the ground surface. The results for blow counts per each 75mm of penetration of the split spoon sampler from a SPT test conducted at the same depth of foundation is shown in Table Q4. Question 4 continued over the page

9 Page 9 of 15 Question4 continued Table Q4. 1 st drive 2 nd drive 3 rd drive 4 th drive 5 th drive 6 th drive 75 mm 75 mm 75 mm 75 mm 75 mm 75 mm A minimum of 25 blows per 30cm has been established as a criteria of acceptance for this foundation to be constructed. Based on the SPT results, comment on the suitability of placing the foundation at this depth. (4 marks) (Total 20 marks) Q5. For the construction of an earth dam, results for compaction tests are shown below in Table Q5. Determine: (a) The maximum dry unit weight of the material and the optimum moisture content. (b) The range of the water content to achieve a 95% of the maximum dry unit weight. Test # Table Q5 Weight of Wet Soil (g) 1 1, % 2 1, % 3 2, % 4 1, % 5 1, % Moisture Content Volume of container = 945 cm 3. Question 5 continued over the page

10 Question 5 continued Page 10 of 15 (Total 20 marks) Please turn the page

11 Page 11 of 15 Q6. An embankment for a highway 30 m wide and 1.5 m thick (rectangular) is to be constructed from a sandy soil, trucked in from a borrow pit. The water content of the sandy soil at the borrow pit is 15% and its void ratio Specifications require that the embankment be compacted to a dry unit weight of 18 kn/m 3. For 1 km length of embankment, calculate: (a) The Dry unit Weight of sandy soil from the borrow pit required to construct the embankment. Assume Gs = (b) The number of 10 m 3 trucks of sandy soil material required to construct the embankment. (c) The weight of water per truck load of sandy soil. (d) The degree of saturation of the in-situ sandy soil. Q7. Resolve the following: (Total 20 marks) (a) A cylindrical sample of wet soil has a diameter of 42 mm and a length of 84 mm. The mass of the sample is 189 g. After placed in the oven, the mass of the sample is 132 g. Assuming that the unit weight of the solids is 2,700 Kg/m 3, calculate the following for the original sample: a. Density b. Unit weight c. Moisture Content d. Void Ratio e. Porosity f. Degree of Saturation g. Air voids content (10 marks) Question 7 continued over the page

12 Question 7 continued Page 12 of 15 (b) A road base, consisting of a sandy material, has been compacted in the field to a 90% of its maximum dry unit weight. The maximum and minimum dry unit weights of the sand are d max = 20.4 kn/m 3 and d min = 13.9 kn/m 3. Determine the field values of: a. The dry unit weight in the field b. The relative density c. The moist unit weight of the sandy material for a moisture content of 15%. END OF SECTION B END OF QUESTIONS (10 marks) (Total 20 marks) Please turn the page for formula sheet for Section B

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