Suspension Bridge - Definition, Types and Advantages

Suspension bridges are a specific type of bridge in which a road has been hung below the small vertical cables that are known as the suspenders. The suspenders of these types of bridges have been connected to the larger cables which have been secured to towers on the other side of the bridge’s deck that has been anchored to the ground.

Suspension bridges do not have massive towers like the other well-known bridges which are made for vehicles. These types of bridges have been made for pedestrians and hikers. The narrow path of the suspension bridges has been made of wood in which suspenders help to connect the deck to the cables thus acting as the bridge thus acting as the railings for those people who are crossing the bridge.

How Suspension Bridges are made of

Different parts are used to make the suspension bridges which include anchors, towers, suspension cables, main cables, and the route. In the suspension bridge, there is an arch in the exceeding span. The route of the suspension bridges hangs from the huge steel cable which has been draped over two towers. These cables are secured into the solid concrete blocks on each end of the suspension bridge which are referred to as the anchorages. The load of the bridge has been transferred into compression within the two towers with the help of the cables. The overall weight of the suspension bridge has been supported by these two towers.

The function of the different parts of the Suspension Bridge

There are different parts of the suspension bridge which has different functions. These functions are as follows:

Towers

This part helps to hold the main cables of the bridge as well as helps to transfer the load of the bridge to the ground.

Main cables

This part of the suspension bridge helps to carry the weight of the bridge deck as well as helps to carry the traffic loads to the towers.

Anchorages

This part helps to anchor the main cables of the bridge to the ground thus helping to resist the tension forces in the cables.

Hangers

This part involves connecting the bridges.

Advantages of Suspension Bridge

There are several benefits of using suspension bridges which are:

Relatively cheap

Suspension brides do not require as much support as other types of bridges. The minimum amount of supplies is required for constructing the suspension bridges which is economical to construct.

Covering long span

The suspension bridges can easily span long distances which is another major advantage of constructing this type of bridge. The suspension bridge can span up to 7,000 feet. In the case of covering 70 feet, 700 feet, or 7,000 feet by the suspension bridge, the support mechanism of this bridge remains unchanged without any kind of compromise towards the bridge’s effectiveness.

Requiring little access

Very little access is required from below to construct the structure of the bridge after the installation of the first temporary cables. Most suspension bridges which are made over water, help to allow the waterway to remain open in the meantime of the construction work. In port cities, the construction of this type of bridge will not interfere with the water traffic which has come in and out of the port.

Different types of Suspension Bridge

There are different types of suspension bridges which include:

Simple Suspension Bridge

This type of suspension bridge is also known as the rope bridge, hanging bridge, swing bridge or centenary bridge. This is one of the simplest types of suspension bridges. The simple suspension bridge is commonly used as the footbridge which is very crucial for the transportation process. This type of suspension bridge consists of a bridge deck and two cables. No anchor blocks or towers are there to provide support to the bridge. In rural areas, this type of suspension bridge is more useful to cross rivers or channels.

Stressed Ribbon Bridge

In this type of suspension bridge, the hanging cables or the suspension cables run by the deck of the bridge. The stress ribbon bridge is also known as the catenary suspension bridge. This type of bridge has been used for the access of the vehicles. This type of suspension bridge has been created from concrete, treated wood or steel rope.

Under-spanned Suspension Bridge

This is the rare variety of spans which has been created within the early 19th century. The trusses of this type of suspension bridge are situated under the deck which helps to enhance the strength of the bridge. This type of bridge spans smaller areas and is made of iron.

Cable-stayed Suspension bridge

This type of suspension bridge is like the span which helps to provide support to the route along with the huge steel cables. In this case, the cables are run from the route up to the tower which helps to form a singular “A” form.

Self-Anchored Suspension Bridge

This type of suspension bridge is the same as the span of smaller areas, but in this case, the end of the main cable has been attached to the deck of the bridge. While it is difficult to construct the anchors on the ground due to the poor soil conditions, this type of suspension bridge has been constructed. On the main cables, the internal forces have been balanced internally without any kind of external support.

Stiffening Truss Suspension Bridge

The elements of both suspension and truss bridges have been combined in this type of suspension bridge. In these bridges, the trusses have been added to stiffen the deck of the bridges thus helping to prevent excessive swaying.

To learn more, watch the following video tutorial.

Video Source: STRUCTURE-TECH

Suspended-deck Suspension Bridge

This is the most commonly available suspension bridge, in which, the bridge deck has been supported by hanging cables. In this case, a very large span bridge can be constructed. Towers, anchor blocks, cables and bridge deck are the main components of this type of suspension bridge.