1. What is Allowable Centrifugal Acceleration?

Definition: The maximum limit for centrifugal acceleration for comfortable travel through vertical curves in road design.

Purpose: Ensures smooth transitions between different grades on highways and roads, providing comfort and safety for vehicles.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( f \) — Allowable centrifugal acceleration (m/s²)
• \( g1 \) — Upgrade gradient (%)
• \( g2 \) — Downgrade gradient (%)
• \( V \) — Vehicle velocity (km/h)
• \( Lc \) — Length of curve (m)

Explanation: The difference between upgrade and downgrade is multiplied by the square of vehicle velocity and divided by 100 times the curve length.

3. Importance of Calculation

Details: Proper calculation ensures comfortable transitions between different road grades, preventing sudden jolts to vehicles and passengers.

4. Using the Calculator

Tips: Enter the upgrade and downgrade as percentages (can be positive or negative), vehicle velocity in km/h, and curve length in meters.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for allowable centrifugal acceleration?
A: Typically ranges between 0.3 to 0.6 m/s² for comfortable travel, depending on road type and design standards.

Q2: How do upgrade and downgrade values work?
A: Both are entered as percentages. A positive value indicates upward slope, negative indicates downward slope.

Q3: Why is vehicle velocity squared in the formula?
A: Centrifugal force increases with the square of velocity, making higher speeds significantly impact the acceleration.

Q4: What if my curve length is very short?
A: Shorter curves will result in higher centrifugal acceleration values, which may exceed comfort limits.

Q5: How does this relate to vertical curve design?
A: This calculation helps determine minimum curve lengths needed to maintain comfortable acceleration levels.

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