1. What is the Vertical Curve Equation?

The Vertical Curve Equation calculates the elevation at specific stations along a vertical curve in road or railway design. It accounts for the base elevation, grade, distance, and curve correction to determine precise elevation points.

2. How Does the Calculator Work?

The calculator uses the Vertical Curve equation:

Where:

• \( base\_elev \) — Base elevation in feet
• \( grade \) — Grade percentage (e.g., 2% = 2)
• \( distance \) — Distance along the curve in feet
• \( curve\_correction \) — Vertical curve correction in feet

Explanation: The equation combines the linear elevation change from grade with the additional correction from the vertical curve geometry.

3. Importance of Station Elevation Calculation

Details: Accurate station elevation calculations are essential for proper road design, drainage planning, and ensuring smooth vertical transitions in transportation infrastructure.

4. Using the Calculator

Tips: Enter all values in consistent units (feet for elevation/distance, percentage for grade). The grade should be entered as a percentage (e.g., 2 for 2% grade).

5. Frequently Asked Questions (FAQ)

Q1: What is a vertical curve?
A: A vertical curve is a transition between two different grades in road or railway design, providing a smooth change in slope.

Q2: How is curve correction determined?
A: Curve correction depends on the type of vertical curve (crest or sag) and is calculated based on the curve length and algebraic difference of grades.

Q3: What are typical grade values?
A: Road grades typically range from -10% to +10%, with most highways using grades between -6% to +6%.

Q4: How often should stations be calculated?
A: Stations are typically calculated at regular intervals (e.g., every 50 or 100 feet) and at critical points like PVC, PVT, and high/low points.

Q5: Can this be used for both crest and sag curves?
A: Yes, the same equation applies to both crest and sag vertical curves, with the curve correction value accounting for the difference.