Question 5: Vertical Alignment (25 Points)

a. (18 points) A section of a proposed undivided 1-lane bidirectional road has a +4% grade and ends at point A with station 0+122.00. It must be connected to another section of the road, which has a 0% grade, at point B with station 1+322.00. It is determined that the crest and sag curves required to connect the two sections should be connected (i.e the EVC of the crest and the BVC of the sag) with a constant-grade section at -3% grade. Design a vertical alignment to connect between these two points using a 60-km/h design speed.

b. (5 points) Sketch the alignment of the entire road section showing the following elements: the grades; BVC, EVC and lengths of crest and sag curves; elevations of BVC and EVC of both curves and constant-grade section; stations of BVC of crest and EVC of sag. Assume elevation of BVC for crest as 0m

c. (2 points) It is given that the elevations at points A and B are 163m and 150m respectively. Comment on the accuracy of the design proposed in step (a). How the design can be improved?

 (You need not provide answers in the box provided below)