CONSTRUCTION PRACTICE
Coursework -1(Contribution 25% of total mark)
Assignment Brief: Assume you are a new graduate and you have recently been employed as a graduate civil engineer, working for a major road Contractor Company “A&C”. The company has assigned you to work on a £4.5million highway constructionproject (1.5 km by-pass around a small rural village) aiming to reduce the trafficcongestion which has existed for many years through its narrow main street. Your first task is to determine the alignment of the new by pass road using information provided by the Consulting Engineering Company called “RD”. To do this, you will need to establish the position of the centre-line of the by–pass road and locate marker pegs at intervals of 25m in the open fields around the village where the road will eventually be built.For this assignment, submit a design and cost report that includes a total of four tasks as indicated below. The following images (Figures 1 and 2) provide you with the background information for the problem of setting out a by-pass road alignmentin the highwayconstruction project.
Figure 1: Typical road alignment with a horizontal curve of a by-pass-road as seen on a map
Figure 2: Typical road alignment of a road section as seen from air
Task 1: Calculate the setting out data (T1, Length of curve, T2, chord and arc length at 25m intervals) for a circular horizontal curve of radius (900+Group no) m connecting two straight road sections between station A and B with a deflection angle (Ɵ) of 18oas shown in Figure 3 below. The chainage of the intersection point is 9500.00m from station A and centre-line pegs are to be located at 25m intervals. Find the chainage of stations T1,T2 and Station B if thedistance between T2 and B is equal to 4500m.Discuss the importance ofthe horizontal curve inhighway design when selecting a road alignmentbetween two places (max 100 words).
Figure 3: Components of a horizontal curve in a road section.
Task 2: Find the earthwork quantities (for both cutting and backfillingoperations) of the1.0 km road section between chainage 94+000 and95+000 m. The reduced levels and design levels of the road section are shown in Table 1. The longitudinal profile and cross-section of the road section are shown in Figure 4 below. Assume atrapezoidal section for both cutting or excavation and backfilling or fillingsections with a side slope (1.3:1) [H: V]. Road width (B) is equal to (18+Group no/4) m. Assume any necessary data to performtask 2 and include justification in the report for any assumptions made.
Table 1: Ground and design level of a 1 km road section at 25 m interval.
SN / Chainage/Station (m) / Chainage Interval (m) / Existing Ground Level (m) / Road Design Level (m)0 / 94+000.00 / 25 / 461.94 / 463.50
1 / 94+025.00 / 25 / 462.07 / 463.40
2 / 94+050.00 / 25 / 462.57 / 463.43
3 / 94+075.00 / 25 / 462.83 / 463.58
4 / 94+100.00 / 25 / 462.35 / 463.86
5 / 94+125.00 / 25 / 462.11 / 464.26
6 / 94+150.00 / 25 / 462.40 / 464.79
7 / 94+175.00 / 25 / 462.99 / 465.44
8 / 94+200.00 / 25 / 463.78 / 466.22
9 / 94+225.00 / 25 / 465.39 / 467.04
10 / 94+250.00 / 25 / 467.59 / 467.87
11 / 94+275.00 / 25 / 469.41 / 468.69
12 / 94+300.00 / 25 / 470.85 / 469.52
13 / 94+325.00 / 25 / 472.19 / 470.35
14 / 94+350.00 / 25 / 473.38 / 471.17
15 / 94+375.00 / 25 / 474.35 / 472.00
16 / 94+400.00 / 25 / 475.01 / 472.83
17 / 94+425.00 / 25 / 475.62 / 473.65
18 / 94+450.00 / 25 / 476.27 / 474.47
19 / 94+475.00 / 25 / 476.92 / 475.21
20 / 94+500.00 / 25 / 477.78 / 475.84
21 / 94+525.00 / 25 / 478.59 / 476.36
22 / 94+550.00 / 25 / 478.88 / 476.79
23 / 94+575.00 / 25 / 478.60 / 477.11
24 / 94+600.00 / 25 / 477.90 / 477.32
25 / 94+625.00 / 25 / 476.94 / 477.43
26 / 94+650.00 / 25 / 476.25 / 477.44
27 / 94+675.00 / 25 / 475.94 / 477.34
28 / 94+700.00 / 25 / 475.85 / 477.14
29 / 94+725.00 / 25 / 475.62 / 476.87
30 / 94+750.00 / 25 / 474.79 / 476.61
31 / 94+775.00 / 25 / 474.06 / 476.41
32 / 94+800.00 / 25 / 473.88 / 476.32
33 / 94+825.00 / 25 / 474.02 / 476.33
34 / 94+850.00 / 25 / 473.97 / 476.44
35 / 94+875.00 / 25 / 473.14 / 476.66
36 / 94+900.00 / 25 / 471.91 / 476.99
37 / 94+925.00 / 25 / 471.38 / 477.41
38 / 94+950.00 / 25 / 473.35 / 477.95
39 / 94+975.00 / 25 / 475.09 / 478.58
40 / 95+000.00 / 0.00 / 477.09 / 479.32
Typical road cross-section
a)Excavation/cutting sectionb) Backfilling section
Depth (m)
Figure 4: Typical longitudinal profile and cross-section of a 1 km road section.
Task 3: Find the project cost of the road section (1.0 km) as shown in task 2, which includes the cost of earthwork and pavement work. Assume the quantities of the earthwork(cutting and filling tasks) are the same asthe quantities calculated in task 2 and calculate the quantities of different pavement layers using information in Figure 5 below. The unit cost of each item is to be selected from the price book of civil engineering and highway works (uploaded in blackboard under workshop/tutorial sub-folder). Assume any necessary data to perform task 3 and include your justification in the report.
Figure 5: Typical cross-section of a road pavement
Task 4: Estimate the quantities and costing of a concrete retaining wall having a total length (950+Group no)m as shown in Figure 6 below. Consider only four activities in the retaining wall: concrete work, formwork, steel rebar and earthworks. Use the unit cost rate of concrete work, steel bars and earthwork from the unit price book of civil engineering works (uploaded in Blackboard). In this task, you can assume concrete C20 (according to BS code) or(C20/25 according to Euro Code 2)in order to find the unit pricefrom the Civil engineering price book for the construction of the retaining wall and also assume the rebar quantityused in the retaining wall (2.5% of total concrete volume). Assume any necessary data and describethe functions ofretaining wallsparticularly in civil engineering aspects(max 100 words).
(Max 25 marks).