Reference no: EM132622085
SEV254 Road and Pavement Engineering - Deakin University
Assessment task 1- Road Design
Details/Questions
On the contour plan shown in the attached topographic map, a critical section of a two-way two-lane rural road is to be constructed with the design speed of 80 km/h, connecting Point A (CH0+000) and Point B near the rural part of Geelong, Victoria. You are required to design the geometric elements of this road section. The design should cover roadway/route location, horizontal and vertical alignments, cross-sectional elements and earthworks for this road to achieve the most safety and economical outcome. The following are the project specific information and constraints supplied by the client:
• The coordinates of Point A and Point B, and terrain features of the area where the road will be constructed are provided in the topographic map (the map is attached in Assessment 1 folder - CloudDeakin).
• There will be only one horizontal curve for this road section (Note: this is to reduce the workload required for this assessment task. For actual projects, the number of curves is reasonably decided based on the topography and other constraints).
• The truck traffic is negligible, hence, only car traffic is considered for the design (Note: this is to reduce the workload required for this assessment task. For actual projects, you may need to consider both cars and trucks).
• Radius of the horizontal curve is given by: R = 240 + 5xt (m), where t is the last digit of your student ID (e.g. t = 1 if the student ID is 987654321). You must check whether this radius satisfies the design requirements or not before using it for the design of relevant road elements.
• Length of vertical curve is L = 140 + 5xt (m), where t is the last digit of your student ID (e.g. t = 1 if the student ID is 987654321). You must check whether this length satisfies the design requirements or not before using it for the design of relevant road elements.
• Traffic lane width is 3.5 m and shoulder width is 1.5 m. The verge dimension is negligible.
• Normal crossfall is -3% for the traffic lanes and -5% for the shoulders.
• Side (batter) slope of cut is 1:1, and side (batter) slope of fill is 1:2.
• Maximum height of fill is 4 m and maximum depth of cut is 5 m.
• The shrinkage factor of soil at the location where the road will be constructed is 5%.
• Street lighting will be provided for this road section
• The earthwork free haul distance is 80 m.
• Other required information can be reasonably assumed in accordance with Austroads Guides.
Given the information and constraints described above, your design should address and answer the following questions (Note: an iterative process may be required to achieve a reasonable design for some geometric elements):
1. Locate and sketch two alternative roadways/routes connecting Point A and Point B on the topographic map showing the length of straight sections and deflection angles. Justify the quality of these two alternative routes and then choose one route for your design.
2. Design horizontal alignment (i.e. tangents, circular curves and transition curves if required) in detail. Develop a horizontal alignment design table showing the chainages (CHs) of all control points on the horizontal curve (e.g. TS, SC, TC, etc.) as well as other relevant parameters that are needed for the calculation of the CHs of these control points.
3. Design the superelevation development (i.e. e, Lrr, Lrg, Le, Sro, Tro, etc.) for the road. Determine the CHs of points at which the superelevations of shoulder and traffic lane start to develop and at which their superelevations end (i.e. back to normal crossfall) (3 marks)
4. Sketch the plane view of the road on the topographic map showing the lengths of straights, circular curve and transition curves (if required), and the CHs of all control points (e.g. TS, SC, TC, etc.).
5. Locate and coordinate your vertical alignment considering vertical controls (i.e. terrain), horizontal alignment control and design constraints. Sketch the profile view of the road that shows the natural ground, the grades and lengths of all grading sections, and the CH and RL of the points of vertical intersection (i.e. PVI).
6. Design vertical alignment (i.e. grades and vertical curves) in detail. Develop vertical alignment design table showing the CHs and RLs of all control points on the vertical curves (e.g. PVI, BVC, Midway, EVC, Apex, etc.) as well as other relevant parameters that are needed for the calculation of the CHs and RLs of these control points.
7. Determine and tabulate the cross section levels at 10 m interval within the superelevated section of the road (from the start of shoulder crossfall development until the shoulder crossfall is back to normal crossfall of -5%) showing the CHs and RLs of left end of the shoulder, left end of traffic lane, road centreline, right end of traffic lane and right end of shoulder.
8. Draw and tabulate the longitudinal section of the road (i.e. profile view) at 100 m interval showing the CHs and RLs, and the depth of cuts or height of fills at all interval points, and the locations and lengths of vertical curves and horizontal curve.
9. Draw cross-sections at 100 m interval showing the road cross-section dimensions, cut/fill batter slopes and natural ground (the depths of pavement and road crossfalls can be neglected). Manually show your area calculations for typical cross-sections (e.g. fully cut, fully fill and partially cut/fill) and indicate all cross-sectional areas in the cross-section drawings (Note: you do not have to draw the cross-sections in correct scale but you need to show all the dimensions).
10. Estimate and tabulate earthwork quantities (i.e. cut and fill volumes, cumulative volume, etc.) using the areas of cut/fill at 100 m interval over the length of the road obtained from Question 9.
11. Draw mass haul diagram and discuss the properties of the mass haul diagram. Calculate the total volumes of earthwork over-haul and free-haul for the entire road section.
12. Check the stopping sight distance requirement for all necessary locations on the designed road. If the stopping sight distance requirement is not satisfied at any locations, provide appropriate solutions (with associated calculations) to ensure safety for road users.
13. As the horizontal curve of the designed road is close to a residential area, the client requires to build sound walls along two sides of the horizontal curve (from the start to the end of the superelevation development) to reduce the impact of traffic noise. Determine the nearest distance of the sound walls from the road centerline to ensure safety for road users.
Attachment:- Road and Pavement Engineering.rar