A bridge arch is a structural design where the bridge takes the form of an upward convex curve. This arch shape is crucial for its ability to support weight and loads.
Understanding the Arch Bridge
The design of an arch bridge is inherently effective for spanning gaps and bearing weight. The key principle is how it distributes the load:
- Load Transfer: Instead of directly supporting the weight vertically, the arch transfers the load partially into a horizontal thrust.
- Abutment Support: This horizontal thrust is then restrained by strong abutments located at either side of the arch.
How an Arch Bridge Works
The arch works like a reverse catenary. Here's a breakdown of the mechanics:
- Curved Structure: The arch is shaped as an upward curve. This curvature is what allows it to transfer the vertical forces into lateral forces.
- Thrust: As weight is applied to the arch, it pushes outward at its base. This is known as the thrust.
- Abutments: The abutments at each end resist this outward push, preventing the arch from spreading and collapsing. This allows the bridge to remain stable and carry loads.
- Distribution: The arch bridge distributes its weight and any other load that is placed on it across the entire structure and down into the ground through its abutments.
Simple Explanation
Think of an arch bridge as a sideways "U" shape. When you push down on the top of the "U", the sides want to push outward. The abutments are like strong walls that stop the sides from moving, which in turn, enables the bridge to carry the weight.
Why Arch Bridges Are Strong
The use of the arch design provides several key benefits:
- Strength: By transferring vertical weight into horizontal thrust, the arch can support heavy loads.
- Stability: The strong abutments provide significant stability, ensuring that the bridge doesn't collapse under pressure.
- Span: Arch bridges can span large distances due to the efficient distribution of forces.
Conclusion
In simple terms, a bridge arch is a structure curved upwards to transfer vertical loads into horizontal thrust. It leverages abutments to maintain stability. According to the reference, "an arch bridge is a bridge shaped as an upward convex curved arch to sustain the vertical loads. A simple arch bridge works by transferring its weight and other loads partially into a horizontal thrust restrained by the strong abutments at either side."
