UNIVERSITY OF BOLTON WESTERN INTERNATIONAL COLLEGE, RAS AL KHAIMAH BENG (HONS) CIVIL ENGINEERING SEMESTER TWO EXAMINATION 2014/2015

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1 OCD54 UNIVERSITY OF BOLTON WESTERN INTERNATIONAL COLLEGE, RAS AL KHAIMAH BENG (HONS) CIVIL ENGINEERING SEMESTER TWO EXAMINATION 2014/2015 GROUND AND WATER STUDIES 2 MODULE NO: CIE5005 Date: Thursday 10 June 2015 Time: am to 1.00pm INSTRUCTIONS TO CANDIDATES: There are SIX questions on this paper. Answer FIVE questions. Answer SECTION A and SECTION B on separate answer books. 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 16 SECTION A Q1 (a) (b) (c) Describe any two of the full range of shear strength testing methods available for different soil types both in the field and in the laboratory. Ensure that your discussions justify the use of specific test methods for specific soil types and also state the advantages and limitations of the methods selected. (7 marks) Explain the Principle of Effective Stress with the help of diagrams and state its Importance. (3 marks) A series of consolidated undrained triaxial tests were conducted on a soil sample (each 38mm in diameter and 76mm long) and the following results in Table Q1 were obtained: Table Q1 Test No : Cell Pressure (kn/m 2 ) Deviator Stress at failure (kn/m 2 ) Pore water Pressure at Failure (kn/m 2 ) Using FigureQ1 on Page 3 and by constructing Mohr s stress circles, determine the Shear strength parameters with respect to effective stress (10marks) Total 20 marks Please turn the page

3 Page 3 of 16 CANDIADTE NO: Figure Q1. TO BE HANDED IN WITH THE ANSWER BOOK Please turn the page

4 Page 4 of 16 Q2. A flexible foundation of length 5m and breadth 3m is to exert a uniform load of 3.75MN. The foundation is to be constructed on the surface of a layer of soil of finite vertical extent of 12m with a bulk unit weight of 21kN/m 3. (a) (b) Determine the immediate settlement under the centre and at the corner of the foundation if the elastic soil stiffness (Eu) is assumed to be 8MN/m 2 (Use Figure Q2-1). (7 marks) For the above foundation, determine the potential damage due to differential settlement (3 marks) Figure Q2-1. Influence values for immediate settlement Q2 continued over the Page

5 Page 5 of 16 Q2 continued. (c) Determine the distribution of Effective stress, Pore Water Pressure and Total Stress at each soil strata using the Figure Q2-2 and hence plot the diagram to illustrate the variation of total stress, pore water pressure and the effective stress with depth from ground surface to a depth of 12m below ground level. The water table is located at a depth of 4m below ground level within a 7m thick deposit of sandy gravel overlying 5m of clay (10 marks) FIGURE Q2-2. Total 20 marks Please turn the page for supplementary information for SECTION A

6 Page 6 of 16 Formula Sheet END OF SECTION A Please turn the page for Section B

7 Page 7 of 16 SECTION B Q1. (a) The reservoir A at a treatment plant feeds two service reservoirs B and C as shown below in Figure Q1. Using the information given in Table Q1-1, make a sensible first estimate for the head at the pipe junction in system A. Briefly explain the reasons for your selections. (4 marks) (b) Use the Flow Balancing Method to approximately determine the flows entering the service reservoirs in Figure Q1. HRS tables are attached on Page Candidates should complete Table Q1-2 provided on Page 15 and hand in with the answer book. (10 marks) A A C B B C Figure Q1: System A Length m Table Q1-1: Details of System A Diameter Roughness Reservoir mm mm Water Level m (AOD) A A 300 B B 284 C C 276 Q1 continued over the Page

8 Page 8 of 16 Q1 continued. Q2. Q3. (c) A 300 mm diameter main conveying water at a flow rate of 170 litres/sec falls 5.0m over a distance of 750m. If the pipeline has a roughness value k s of 1.5mm and the pressure at the end is 3 bars, determine the pressure at the start in kn/m 2. (HRS Table is provided on Page 13-14). (6 marks) Total 20 marks (a) A 500 mm diameter, 3000m long pipe is used to connect the two reservoirs for a discharge of 280 litres/s through the pipe. If the discharge is to be increased to 500 litres/s, what will be the length of a parallel pipeline of diameter 750 mm to be provided to accommodate the flow if the frictional head loss remains the same? Take λ= 0.03 for both pipes. Neglect all minor losses. (14 marks) (b) Sketch out the general shape of the Stanton (or Moody) diagram for flow through pipes and briefly explain the factors which affect the value of the Darcy friction factor in each of the zones. (6 marks) Total 20 marks (a) An old water main, having a k s value of 0.03mm, has a diameter of 200mm and is 800m in length. When the flow rate Q is 50 litres/sec, the pressure recorded at the inlet is 5 bar and the pressure recorded at the outlet is bar. Determine the difference in the pipe levels at the inlet and outlet. Take the coefficient of kinematic viscosity for water as 1.14 x 10-6 m 2 /sec. (15 marks) Q3 continued over the Page

9 Page 9 of 16 Q3 continued (b) A foul sewer, with pipe roughness ks of 1.5mm, is to be designed to serve 625 houses. For a housing occupancy of 3 persons per dwelling and water consumption of 175 litres/head/day, determine a suitable pipe diameter and gradient. Assume appropriate estimates for design factor and infiltration. Justify your assumptions. HRS tables are provided on Pages (5 marks) Total 20 marks Q4. (a) Explain what is meant by the term "combined sewerage system" and outline its operational benefits and drawbacks as compared to other sewerage systems. (6 marks) (b) Details of an existing surface water sewer system are given below in Table Q4-1 in Page 10. The pipes in the system have pipe roughness k s of 1.5mm and the time of entry for surface water is 4 minutes. Using the Rational method, complete Table Q4-2 provided on Page 16 and check whether the system is capable of withstanding a storm of 1 in 2 years return period. Rainfall Table and HRS tables are provided on Pages 12 & respectively. (14 marks) Q4 continued over the Page

10 Page 10 of 16 Q4 continued Table Q Ref No length (m) gradient (1 in ) Imp. Area (ha) dia. (mm) Total 20 marks END OF QUESTIONS Please turn the page for supplementary information for SECTION B

11 Page 11 of 16 Formulae Sheet h f = S o L z v 2g P g v 2g P g z2 hf Q = A v h f = L v 2 2 g d h f = L Q d 5 h f = S o L Re = v d = v d 1 ks 2log 3.7d Re 89 Q = 2.78 A p i Please turn the page

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15 1 st estimate H j =.m Page 15 of 16 Table Q nd estimate H j =..m 3 rd estimate H j =.m h f across S O Q h f across S O Q h f across S O Q (m) (1 in) (litre/s) (m) (1 in) (litre/s) (m) (1 in) (litre/s) A B C Error in Q = l/s Error in Q = l/s Error in Q = l/s TO BE HANDED IN WITH ANSWER BOOK Table Q4-2. Candidates ID No... Please turn the page

16 Page 16 of 16 length ref No length (m) gradient (1 in ) Vel (m/s) Time of flow (min) Time of Conc. (min) Rate of rainfall i (mm/hr) Imp. Area (ha) Cumulative Imp. Area A P (ha) Flow Q (l/s) dia. (mm) TO BE HANDED IN WITH ANSWER BOOK Table Q4.2 END OF SECTION B END OF PAPER Candidates ID No...

UNIVERSITY OF BOLTON WESTERN INTERNATIONAL COLLEGE FZE BENG (HONS) CIVIL ENGINEERING SEMESTER TWO EXAMINATION 2016/2017 GROUND AND WATER STUDIES 2

OCD27 UNIVERSITY OF BOLTON WESTERN INTERNATIONAL COLLEGE FZE BENG (HONS) CIVIL ENGINEERING SEMESTER TWO EXAMINATION 2016/2017 GROUND AND WATER STUDIES 2 MODULE NO: CIE5005 Date: Saturday 27 May 2017 Time: