095 BS 2854 IS 2988 IS 1982 IS 1128 IS 3567 IS 3497 FS 2238 BS 2561 IS 325 IS

# 095 bs 2854 is 2988 is 1982 is 1128 is 3567 is 3497

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the order taken are 3.095 (BS), 2.854 (IS), 2.988 (IS), 1.982 (IS), 1.128 (IS), 3.567 (IS), 3.497 (FS), 2.238 (BS), 2.561 (IS), 3.25 (IS), 3.372 (IS), 1.341 (IS), 1.604 (FS). Book these readings and apply all checks. (15 marks) Q2. (a) Briefly explain the reasons behind observing angles in both faces when measuring angles in a traverse. Line Distance (metres) Observed Lefthand Angle 0 , " 30 35 54 AB 1581.741 BC 442.260 31 43 28 139 59 08 195 33 02 152 19 32 169 50 14 CD 402.474 DE 338.158 EF 307.821 FA 213.915 (15 marks)
SAD 10231 SZW 1023 -2- Q3. (a) Discuss briefly the characteristics of a spiral curve that makes it useful in road curve designs (6 marks) (b) On a section of an existing road, two straights that intersect at chainage of 1873.62m and at an intersection angle of 168 0 52' 12" are joined by a wholly circular curve that has a dangerously small radius of curvature. It is proposed to replace this with a combined curve consisting of a 120m long transition curves at each end and a circular in the middle. The design speed and rate of change of radial acceleration are to be 100 kmlh and OJ m/s 3 i) The chainages of the start and end of the central circular curve. ii) The setting out data of the first transition curve at 25m intervals. (14 marks) Q4. (a) Sighting distances and K-values are two criteria considered in vertical road constructions. Explain briefly how these are used when deciding the length of a vertical curve. 3.l6m. A parabolic vertical curve having equal tangent lengths is to be used to connect the two gradients, which meet at chainage 2619.52m. A K-value of 20 was used to obtain the curve length. Calculate the chainage and reduced level of the point at which flood water could be collected and drain away quickly to reduce the flooding period. (14 marks)
SAD 10231 SZW 1023 - 3- Q5. (a) Using a suitable diagram, explain what is meant by radiation in detail surveying. (10 marks) (b) Table Q5 lists some of the observations recorded from a detail survey conducted for the purpose of constructing a bridge across a canal. Observations were made from station P which was located near the canal. The coordinates of Pare 14598.514m Nand 66619.188m E. A nearby station, Q whose coordinates are 14550.164m Nand 66525.819m E was sighted as backsight station. Table Q5 Horizontal Angle Reading 0 , " 95 04 14 250 16 24 312 43 16 Horizontal Distance Remarks (Detail) - Station Q - Backsight 50.351 Point X - Bank of canal (south) 96.654 Point Y - Bank of canal (north) If the proposed bridge is to be built from point X to point Y, then calculate its bearing and length. (10 marks) 1'-\ 7 {~ \~i I
SAB 10231 SZW 1023 -4- Q6. (a) Using appropriate illustrations, briefly discuss the various type of cross-sections that can exist. (6 marks) (b) A planimeter was used to measure the plan areas contained between the proposed position of a dam wall and several contour lines on a 1: 10000 scale map. The planimeter areas shown in Table Q5 were obtained. The proposed mean water level of the reservoir is 93m and the volume below the 40m contour can be neglected. Calculate the vo lume of the reservoir to the nearest 1000m 3

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