SURVEYING FINAL ASSIGNMENT

SURVEYING FINAL ASSIGNMENT   (ROAD DESIGNS for LINES A and B)

A sketch map with contour lines at 25m intervals is provided. The red lines on the sketch map show two possible new road alignments (A and B), which will carry large numbers of heavy trucks, to by-pass a small town. The start and finish of each bypass is on the natural surface. The bearing and distance of each straight is shown and the radius proposed for each of the horizontal curves is also shown.
The green lines are existing major roads.  The land both routes will pass through is developed farming land in private ownership.
The proposed routes have been drawn by bureaucrats, where their main aim is to avoid existing houses.

Where possible the road should follow the natural surface minimising cut and fill.  The proposal has now been passed to the Engineering Department to assess the two possible routes. Your task consists of the following four parts.

1. Using the horizontal curve data shown (where R is the radius of each curve) calculate the length of each bypass (to 1 decimal place).   Also list the chainages of each T.P. along each road. It is not necessary to show all of your working/calculations, but it would be good to show the results of individual calculations.
2. Some members of council have asked for clarification about the proposed road options as they do not understand the plan provided.

For each road, section by section, as shown at the bottom of the page, describe the road’s horizontal alignment in a sentence or two.
In a few paragraphs, describe the longitudinal slopes of the natural surface along each section.  Explain where you would expect substantial vertical curves to be needed in the road design by suggesting appropriate I.P. locations.  Further, you must draw attention to any structures that would be needed, such as bridges and bridge approaches.  Also identifyany areas where you would expect large depths of cut or fill to occur, or difficulties in meeting the design criteria due to the grade of the land.

3. While the entire road will need to eventually have a final accurate survey completed, for those areas that you have mentioned in part 2 above, to assist with assessing each road’s suitability, more detailed survey work on site will beundertaken immediately. As part of this section, you must suggest possible R.L.s for the decks of any bridges and the impacts that those R.L.s will have on the road design.As part of this assessment process you may also wish to recommend areas to investigate for possible minor horizontal deviations  (for example, less then 800m in length and less than 150m sideways deviation) to be included in such survey work if you feel it would help the road design.  Please describe what information each of those site surveys should obtain. 
4. Which line (A or B) would you recommend being adopted? In no more than one page give your reasons for making this decision.

You may find it helpful to draw a longsection of each proposed road.

You should prepare your report on the basis that a maximum grade along the road of 7% is proposed.
River Characteristics
The river is tidal, so assume that the blue line showing the river edge is at R.L 2m.  It will flood to an R.L. of 7m once every 10 years.  There is an island in the river where Route A crosses the river.

Report

Please use the following layout for your report. An Answer sheet with headings has been provided.
i) Part 1 – Length of bypass and chainages of each TP.
ii)  Road A: Section 1, Horizontal Alignment, Vertical Alignment etc., Extra Survey work needed;  then same layout for Sections 2 and  3 of Road A.  (No more than a page or page and a half of writing is needed for each road)
iii) Road B: Section 1, Horizontal Alignment, Vertical Alignment etc., Extra Survey work needed;   then same for Section 2 of Road B.
In your report, please use contour lines, or approximate chainages (or both) to clearly identify the location of features you are referring to e.g.  “at the 75m contour line at approx. Ch 5.4km”

Road Sections

Road A -Ch 00 to T.P. 3 (the start of the 690m radius curve) – T.P. 3 to T.P. 5 (the start of the 880m radius curve) – T.P. 5 to the end of road A.

Road B – Ch 00 to T.P. 1 (the start of the 800m Horizontal Curve) – T.P. 1 to the end of road B

 

Please prepare your report using the word document provided, which you must submit for marking.  About a half a page of writing will be enough in discussing each section of a road.