An arch is supported by the keystone, the wedge-shaped stone at the top of the arch, and the voussoirs, the individual stones that make up the arch.
Understanding the Structure
- Keystone: The keystone is the most important part of an arch because it bears the weight of the entire structure. It is wedged tightly between the voussoirs, preventing the arch from collapsing.
- Voussoirs: The voussoirs are arranged in a curved shape and are carefully cut to fit together perfectly. They are held in place by their own weight and the pressure from the keystone.
Supporting an Arch:
- Buttresses: Buttresses are external supports that are used to reinforce arches, especially in large structures like cathedrals. They act as counterforces to the outward thrust of the arch.
- Thrust: The inward pressure exerted by the arch on the supports is called thrust. This thrust is what makes arches so strong.
- Arch Ring: The arch ring is the curved structure formed by the voussoirs and the keystone. It is essential for transferring the load from the arch to the supports.
Examples of Arches:
- Roman Aqueducts: These ancient structures used arches to carry water over long distances.
- Bridges: Arches are often used in bridge construction to provide strength and stability.
- Buildings: Arches can be found in many buildings, from ancient structures to modern skyscrapers.
Practical Insights:
- The shape of an arch is crucial for its stability. A properly shaped arch can withstand a great deal of weight.
- Arches are often used in conjunction with other structural elements, such as columns and beams.
- The materials used to build an arch can affect its strength and durability.
