13.1. A reverse curve

Try these first

1. 1.

   Define chainage in your own words.

   Hint

   Think about how distances are measured in road construction.

2. 2.

   What is the formula for calculating the length of a circular curve?

   Hint

   Consider what each of the letters represents.

3. 3.

   What is the primary purpose of calculating chainage?

   • To measure curves
   • To establish the position of points
   • To define road width

   Hint

   Think about how this helps in construction.

4. 4.

   True or False: The deflection angle is not important in reverse curves.

   • True
   • False

   Hint

   Consider the implications of a poorly defined curve.

5. 5.

   How would you calculate the radius required for a reverse curve if given the distance between two tangents is 60m and a vertical separation of 12m?

   Hint

   Use tangent relationships to establish the correct formula.

6. 6.

   Calculate the offsets for different chords along a reverse curve with a radius of 700m over an angle of 90°.

   Hint

   Consider the lengths of chords effectively during calculations.