18. Example 2.26:

Try these first

1. 1.

   What is the formula to calculate the length of a vertical curve?

   Hint

   Consider the difference in grades and the rate of change.

2. 2.

   If point A has an RL of 350 m and is on a +1% grade, what is the RL at point O, 180 m away?

   Hint

   Calculate the drop using the grade.

3. 3.

   What formula is used to determine the length of a vertical curve?

   • L = (g1 - g2) * r * 30
   • L = g1 + g2 - 30
   • L = g1 / g2 * 30

   Hint

   Remember the relationship between grades and length.

4. 4.

   The RL of a point is lower if it has a negative grade.

   • True
   • False

   Hint

   Think about the meaning of a negative grade.

5. 5.

   Given a grade change from +1% to -3% over a 600 m stretch, calculate the length of the vertical curve and the RL for points located 120 m before and after the intersection.

   Hint

   Can you apply the grade and distance effectively?

6. 6.

   A vertical curve connects two grades of +0.3% and -0.9%. Given the RI at the intersection is 310.5 m, calculate the RL at the midpoint of the curve with a length of 180 m.

   Hint

   Break down how the elevation affects the drop specifically.