Assignment 1

 Question 1

a.

Draw a Gantt Bar chart representing the above events, depicting: activity and duration, total float, critical path and duration.

b. List the most appropriate type of contract and discuss the reasons for your conclusion for the following tenders:

(i) The supply of three (3) robotic total stations plus specified associated equipment;

(ii) The supply and delivery of cadastral survey pegs and stakes to a large residential subdivision at a specified location - approximately 2000 to 3000 units for each item.

Question 2

a. The following natural surface levels were taken along the proposed centre line of a road:

An equal tangent parabolic vertical summit curve is to be placed between two successive design formation grades of +3.0% and -2.0% which meet at a point 700m at a reduced level of 33.2 m. The length of the curve is 200 m. Compute and tabulate:

i. the calculated RL’s of the chainages/meterage along the tangents;

ii. the reduced levels of the design surface;

iii. the cut(-ve) or fill(+ve) required at each peg at the centre line.

b. The centre-line of two railway culverts is required to be set-out from the start of a transition curve, curving to the right. Calculate the deflection angle and chord from the start of the transition curve using the rigorous ideal transition curve formulae, using the following data:

Intersection angle = 20o19'50"

Radius = 350m

Transition length = 50 m

Start point (TS) of transitioned curve = 565 m

(i) Chainage/meterage of culvert one = 610 m

(ii) Chainage/meterage of culvert two = 680 m

c. A surveyor when placing a fill situation catch point mark for batter marking, measures the modelled catch point by the following data and given information:

Height of collimation of level = 87.0 m

Design centre-line level = 86.15 m

Distance from the design centre-line to edge of shoulder = 5.0 m Pavement crossfall from the design centre-line = -3% Shoulder batter (-ve for fill situation) = -1: 0.5 (horizontal to vertical) or -2: 1

Natural surface staff reading for catch point = 2.43m, taken at the 8m modelled offset from the centre-line as read off the construction tables.

Calculate if the catch point is in the correct modelled position, and if not, what would be a suggested shift, assuming the ground is level, apply a check to your solution.

Question 3

a. Robert from River Adventures runs a white-water rafting company and tells you that the Clearwater River varies in height over the season by about 5 metres and this affects the raft speed. Based on the information below.

Roughness coefficient = 0.025

Hydraulic gradient = 0.016m/m

Acceleration due to gravity = 9.8m/s2

Calculate the (i) hydraulic radius and velocity of flow by Manning’s Formula and (ii) rate of flow per hour for both the high water and low water marks.

b. The top of a pile requires final placement at E 100.8, N 200.6 and RL 50m (say for bridge/wharf/jetty construction). The pile is angled away from the centre-line along the line of the piles, into the sub-surface at a +10o angle off normal. The bridge centre-line has a bearing of 20o and the required line of piles to the left of the centre-line has a bearing of 290o. A measurement to the current position of the pile top has been reduced to be at E 101.5, N 200.1 and RL 55.9m. Calculate the required movement of the pile top, so as to be positioned to commence driving at RL 55.9m, along the line of skew. See plan and elevation views below

c. A flight of levels is run from a Bench Mark of R.L. as per the table below and the following readings obtained: 

At CP4 position of the level, six height pegs at 20 metre intervals (100m in total) are to be set out at a falling grade of 1 in 420. The first peg (i.e. 00) has a design level of 86.20m.

Calculate the grade levels and staff readings required for the top of each peg using the Height of collimation booking method and enter the results in level book form.