Centering

Definition

Centering refers to the temporary framework or support system used during the construction of arch bridges to hold the arch elements in place until they are self-supporting. This technique is crucial for ensuring that the arch maintains its shape and alignment while the materials set and cure, ultimately providing stability and integrity to the bridge structure.

5 Must Know Facts For Your Next Test

1. Centering is typically made of timber or steel and is designed to be removed once the arch has gained sufficient strength.
2. Proper centering is essential for achieving the correct curvature of the arch, which directly affects the load distribution and overall stability of the bridge.
3. The design and construction of centering must account for various factors including weight, environmental conditions, and construction methods.
4. Adjustments may be necessary during construction to ensure that the centering remains aligned as the arch components are placed.
5. Failure in centering can lead to misalignment or collapse of the arch before it can support itself, highlighting its importance in arch bridge construction.

Review Questions

• How does centering contribute to the structural integrity of an arch bridge during its construction phase?
  • Centering plays a crucial role in maintaining the shape and alignment of an arch bridge during construction. It supports the individual components of the arch until they can bear loads independently. If properly constructed, centering ensures that the curvature is maintained, which is vital for distributing loads effectively across the structure. Without it, there is a high risk of misalignment or even collapse before the bridge is fully complete.
• Discuss the various materials used for centering in arch bridge construction and how they impact construction efficiency.
  • Centering can be made from different materials such as timber or steel, each impacting construction efficiency differently. Timber is often favored for its ease of handling and lower cost but may require more frequent adjustments due to its flexibility. Steel, while more expensive, offers greater strength and durability, allowing for quicker assembly and disassembly. The choice of material can significantly influence both the speed of construction and the overall safety of the project.
• Evaluate the consequences of improper centering during arch bridge construction and how this can affect long-term performance.
  • Improper centering can have serious consequences, leading to misalignment or even failure of the arch before it becomes self-supporting. This misalignment can result in uneven load distribution, which may compromise not just the immediate safety during construction but also affect long-term performance by causing undue stress on certain sections of the bridge. Over time, this could lead to structural weaknesses or even catastrophic failures, emphasizing that effective centering is vital not just for short-term success but also for ensuring long-term durability and safety of arch bridges.

Related terms

Arch:

A curved structure designed to support loads, often used in bridge construction, where the shape helps distribute weight and provide stability.

Scaffolding:

A temporary structure used to support work crews and materials during the construction or repair of buildings and bridges, ensuring safety and accessibility.

Formwork: The molds used to shape concrete or other materials during construction, providing support until the material hardens and gains sufficient strength.