Cantilever Bridge | Cantilever Bridge Advantages and Disadvantages | Cantilever Bridge Facts

Cantilever Bridge

A cantilever bridge is a specific type of bridge. It is called a cantilever bridge because it is built using cantilevers. A cantilever is a structure that is only anchored at one of its ends. Its other end projects horizontally into space, and it is this end that helps support the bridge.

Cantilever Bridge Advantages

During the bridge’s construction, which is done from each support pier, navigation below the bridge is not obstructed. Bridges are frequently constructed across roads and challenging crossings, allowing uninterrupted traffic flow. Because the beams can be attached at the extremities of the cantilevers, the span (section of a bridge between two adjacent piers) of these bridges can be longer than traditional beams. Suspended truss bridges (assembled sections) are simple to raise and connect two cantilever spans. The deck (bridge surface) can be simply built-in segments, ensuring quality and regularity.

Disadvantages of Cantilever Bridge

Although cantilever bridges usually last for years, the potential for failure is greater when the bridges are not attached to the strong teeth found in the back of the mouth. may be damaged. Because they are anchored on only one side, the risk of cracking or debonding is slightly higher than other bridges.

Cantilever Bridge Pros and Cons

Pros of Cantilever Bridges

Here the list of advantages of Cantilever Bridges are as follows.

• The floor of the bridge is simply formed into sections to preserve uniformity and ensure high quality.
• It is less time-consuming, As multiple cantilever spans construction can be started simultaneously from all its columns.
• Navigation or passage under the bridge is not disturbed during the construction
  process.

Cons of Cantilever Bridges

Here the list of disadvantages of Cantilever Bridges are as follows.

• A cantilever bridge requires a heavier structure to take care of its own stability by creating stability between compressive and tensile forces.
• During the construction of Cantilever bridges, they experience a high level of tension which is known as negative moments.
• Cantilever bridges cannot be constructed in extreme climate conditions due to the lack of multiple seasons.
• Cantilever bridges require advanced analysis to prevent future fatigue failure of elements and welds.

Advantages of a Cantilever Bridge

The Pros of Cantilever Bridges

• They are less invasive. Because they only require impacting one other tooth, less natural tooth surface is disturbed.
• They look natural.
• A cheaper alternative.
• Their longevity makes them attractive.
• The healthier alternative.
• They are easy to place.

Cantilever Bridge Facts

A cantilever bridge is generally made with three spans, of which the outer spans are both anchored down at the shore and cantilever out over the channel to be crossed. The central span rests on the cantilevered arms extending from the outer spans; it carries vertically.

Cantilever Bridge Features

Cantilever bridges can be built without false-works below nor temporary supporting towers and cables above. It is one of their great advantages. They are also of very rigid construction so they can carry large loads without threat for construction.

Advantage and Disadvantage of a Cantilever Bridge

Overall, cantilever bridges offer many advantages, including their versatility, strength, and ability to span long distances. However, these bridges are only suitable for some conditions, as the construction process can be complex and expensive and may not be suitable for carrying high loads.

What Are the Advantages of a Cantilever Bridge?

• Structural Stability
• Flexibility in Span Length
• Resistance to Tension
• Durability
• Cost-effectiveness

Cantilever Bridge Cons

Although cantilever bridges typically last for years, there is a higher chance of failure when bridges are not attached to the sturdier teeth found at the back of the mouth. Damage may occur. Because they are only anchored on one side, there is a slightly higher risk of cracking or debonding than with other bridges.

Cantilever Bridge Characteristics

1. Support: Cantilever bridges rely on a support system that consists of a pier or a solid foundation at one end, known as the “fixed support.” This support provides the necessary stability for the bridge structure. The other end of the bridge extends without any intermediate supports, creating a cantilevered section.
2. Structural Elements: Cantilever bridges typically consist of three main structural elements: the cantilever arms, the suspended span, and the anchor arms. The cantilever arms are the sections that extend from the fixed support towards the center of the bridge. The suspended span is the section that connects the two cantilever arms, and it is often supported by additional stays or cables. The anchor arms extend from the center of the bridge to the opposite side, providing additional support and balance.
3. Tension and Compression: Cantilever bridges rely on a combination of tension and compression forces to distribute the weight of the bridge and provide structural stability. The cantilever arms are subjected to compression forces, while the suspended span experiences tension forces. This balance between tension and compression allows the bridge to support its own weight and any additional loads.

What Are Cantilever Bridges Used For?

Cantilever bridges are designed for road or rail traffic and typically built from structural steel or boxed girders made from prestressed concrete. The defining feature of a cantilever bridge is, well, a cantilever. Cantilevers are structures that project horizontally with support on only one end.

How Does a Cantilever Bridge Work?

A cantilever bridge works in the same way: the bottom part of each cantilever is anchored into the ground, while the upper end of the cantilever supports the bridge itself. Some cantilever bridges are small enough to use simple beams to support the bridge itself, like the Kingsgate Bridge in Durham.

Types of Cantilever Bridge

• Balanced Cantilever Bridges. The balanced cantilever bridge does not require any falsework.
• Continuous Cantilever Bridges. The continuous cantilever bridge is a truss bridge that extends across three or more supports without hinges or joints.

Are Cantilever Bridges Strong?

A cantilever bridge differs from other bridges in that it is only anchored in place on one side instead of two. Often used when there is only one adjacent tooth to support the bridge, they are almost entirely as strong as their traditional counterparts.

What Is the Purpose of a Cantilever Bridge?

Function. Cantilever Bridge. —A structure at least one portion of which acts as an anchorage for sustaining another portion which extends beyond the supporting pier. A simple cantilever span is formed by two cantilever arms extending from opposite sides of an obstacle to be crossed, meeting at the center.

What Is One Advantage and One Disadvantage of a Cantilever Bridge Design?

One advantage of a cantilever bridge design is its ability to span long distances without the need for intermediate supports or piers. This makes it suitable for crossing large bodies of water, wide valleys, or areas where it is difficult to construct intermediate supports.

One disadvantage of a cantilever bridge design is the complexity and cost associated with its construction. Cantilever bridges require careful engineering and precise construction techniques due to the unique balance of tension and compression forces.