SURVEYING FINAL ASSIGNMENT (This assignment is marked out of 80 but is worth 40% of the subject assessment)
Using the plan provided, and meeting the criteria set out below, you must make a preliminary design for a road to access a rural property. The new road must run from its junction with Tucker’s Road and must end inside the parking area (labelled P) at exactly the R.L. specified and must not be longer than 520m. Also, a survey party will undertake a final survey on your behalf and you are to provide them with instructions for any extra data to be collected as well as data to allow them to set out the road.
The plan provided was drawn at a scale of 1:2,000 with a contour interval of 5m.
While every effort was made when scanning the plan, and recognising possible printer variations, you MUST CHECK the scale of your print. As well as the bar scale showing 100m, there are three lines , for which precise distances have been given. Measure each of the four lines at a scale of 1:2,000, show these measurements in your answer sheet and compute a correction factor for your plan. State this factor and use it when you measure the lengths of your straights.
Assume that the contours are correct with 90% confidence.
The first straight is shown in red and the first Intersection Point (IP) must be at the end of the red line.
You must draw two more straights to complete the road alignment. These straights must allow the road to be designed to meet the requirements of the vertical design as listed below. Also, the area of land adjacent to the creek, which runs to the river, that is bounded by the 15m contour line, the river and the two dashed lines is prime agricultural land and the road is not permitted to go through this area.
Use a protractor to find the bearing of the first straight and then measure the deflection angle for each curve to the nearest degree. Use Tucker’s Rd with its bearing of 0o, as your azimuth. Scale the distances from Tucker’s Rd to IP1, IP1 to IP2 and IP2 to the End, to the nearest metre. For the purposes of the calculations for the preliminary design, the scaled lengths (00 – IP1, IP1 – IP2 and IP2 – END) must be adopted as the design length of each straight to a precision of two decimal places.
Each horizontal curve is to have radius of 60m.
Calculate the tangent distance and arc length for each curve and show them in the table of answers.
Calculate the chainages of each of the four TPs and any other points listed and show them in the table of answers.
On your plan, plot each curve. (Calculating the external distance will give you a third point to help you draw the curve freehand.) Also clearly show the lengths of each straight (IP – IP) and the bearing of that straight.
Please calculate the data needed to set out each horizontal curve from its first TP by deflection angles and long chords for points at 15m running chainage along the road as well as the crown of each curve. (i.e. 120, 135, 150, 165 … 360, 375, 390, 405, as they fall within each horizontal curve.
Using the contours on the map provided, draw a longsection of the Centre Line of your road at scales; horizontal 1:2,000 and vertical 1:200. (Please read the submission section for detailed guidance about drawing the longsection.)
Design a vertical alignment of the centre line of the road showing grades and vertical curves. The vertical alignment must meet the following criteria:
The road must start at RL 14.5 and must finish at exactly RL 32.5. This final grade of your road into the parking site must be between +2.0% and +0.5%. The maximum grade allowed at any point along the road is 10%.
Vertical curves must have lengths of 60m or 80m only. In exceptional circumstances, a VC of 40m length may be permitted but you will need to explain why it must be used. The IP of each vertical curve must be located at an even 10m chainage (i.e. 120, 350 etc. and must not be placed at odd locations such as 376.5). All grades used must be to no greater precision than 0.1%, except for the final grade to the end of the line. (i.e. grades such as 3.1% must be used for every grade, except the final one where additional decimal places must be shown, where necessary, to ensure that the Design RL meets the set RL of the parking area).
Every change of grade requires a vertical curve. (Assume that your road will meet Tucker’s Road at the nominated RL and can start at any grade you wish to use. No vertical curve will be needed at this road junction.)
Cut and Fill
Except for the two locations specified, the vertical design should keep cut and fill to less than 1m in depth. Working by eye, and not mathematically, try to balance cut and fill along the road.
Between the two banks of the river, your road must be between 1m and 2m above the bank R.L., so that precast box culverts can be installed. For no more than 15m either side of the 30m contour line, a cut of up to 2m is permitted.
Complete the table with your vertical curve calculations for the design levels.
Calculate the Design Levels for the locations as specified: every 30m of running chainage along the road, where there is NO vertical curve; (i.e. 0, 30, 60, 90 …300, 330, 360 etc. … and the end of the road). For every vertical curve, please calculate the Design Levels at every 10m from VC TP to VC TP.
Also calculate the chainage (to 2 d.p.) and RL of the low point of the road at the river crossing.
The banks of the creek where the road crosses it are at R.L. 11.0.
Precision of Calculations Needed
On your plan, please show the bearings of the straights to the nearest degree only and the distances IP to IP should be shown to the nearest metre.
For the horizontal curve setting out data, please calculate the arc lengths and long chord distances to two decimal places of a metre and the setting out deflection angles to the nearest 10”.
All levels on the longsection table must be correct to two decimal places. The grades you nominate for the road design must be to no greater precision than one decimal place, except for the final grade, and all R.L.s must agree perfectly with the grade shown. Your road must end exactly at R.L. given for the parking area.
Survey Party Instructions
A survey party has run an EDM traverse point A, (whose coordinates are 300.000m E, 600.000m N) on the centre line of Tucker’s Road via point Y, to a point X which is close to the parking area P. Calculate the coordinates of point X. Also, using your bearings and distances of each straight of your road, calculate the bearing and distance for the survey party to set out the end of your road from point X.
The curve set out data has already been requested.
Finally provide instructions to the survey party for any extra information needed or areas to checked for you to be able to finalise your road design.
1) The plan showing your straights with the bearings and the scaled distances (0 to IP1), (IP1 to IP2) and (IP2 to the END) clearly marked. Each horizontal curve must be plotted.
2) Horizontal and Vertical Curve Tables completed on the answer sheet.
3) A Longsection, showing:
a) in the drawing section, the natural surface, grade lines and the road design. You must also note the extent of each grade and the regions where the vertical curves are located. Also show each IPRL and Mid Ordinate value, as per the example provided.
b) in the data rows, the distances and natural surfaced RLs used to plot the natural surface;
the distances and Design RLs at the chainage of each IP of the vertical alignment only.
(Longsection guidance – it is strongly recommended that you use an A4 sheet of 2mm graph paper to draw your longsection. The bottom three rows should show Distance, Design RL and Natural Surface RL. To ensure your longsection fits on the page, the RL of the base line of the plot should be 5m, making the very top of the page RL 33m.) See a detailed example online.
4) Instructions for the survey party:
a) data to mark location of the end of your design from point X, (as per the tables provided)
b) data to set out each horizontal curve from its first TP by deflection angles and long chords for points at 15m running chainage within each horizontal curve, and the crown of each curve, (as per the tables provided)
c) instructions to the survey party for any extra information you wish them to gather for you to finish your design.
Submission Component and Marks Awarded
Plan 1) 6 Horizontal Curve calcs (leading to chainages) 2) 14 Longsection 3) 5 VC Calc table: Grades, ordinates, Design RLs 2) 20
Low Point Ch and RL 2) 5 Design meeting specifications 3) 5 Traverse and missing line calculations 4)a 10 Curve set out data 4)b 10 Instructions to Survey Party 4)c 5
This exercise is only an assessment of the work done in the Surveying subject this semester. Do not research road design information and go beyond the calculations shown to you in the Surveying classes. You will be marked on the accuracy of your calculations and meeting the specification only. The “quality” of the road design will not be considered. i.e. treat the horizontal and vertical alignments as being totally separate designs.