In recent years, bridges are just structures used for sight-seeing. A bridge is just something that gets people, animals and vehicles from point A to point B. But bridges have that ability of fulfilling man’s insatiable need to discover what else is out there, making them one of our most important architectural inventions. Here are just a few of the different types of bridges that are out there.
Fixed – Fixed bridges are the type of bridges that have no movable parts.
Movable – As opposed to fixed bridges, moveable bridges have moveable parts. These types of bridges are usually used on bridges that are used over bodies of water where boats and ships pass through.
Temporary – These bridges are usually made from lightweight modular components, making for easy transport. They are usually used when a bridge is being repaired as an alternative for commuters or traffic.
Beam – The beam bridge is the simplest and most common type of bridge construction. A horizontal plank (beam) runs across the gap and is supported by columns (piers) underneath. The farther apart the spaces between piers the weaker the bridge is, which is why most beam bridges are less than 250 meters in length.
Arch – In terms of design, the arch bridge is the most reminiscent of the olden days. The focus of an arch bridge’s design is the arch (could be one or more depending on the length of the gap) that’s located underneath the beam. Not surprisingly, the arch bridge is one of the most naturally strong designs for bridges. The arches properly dissipate the force applied on the bridge, therefore taking away much of the tension coming from underneath the structure.
Truss – Among the modern bridges, the truss bridge is among those with the oldest designs. It is easily characterized by having triangular units along the span of the bridge. Some designs have these triangular units above the beam (through truss), while other have it below the beam (deck truss).
Suspension – The suspension bridge is the bridge of choice for large gaps. A suspension bridge can span as long as 4,000 meters. As its name suggests, the beam in the suspension bridge is suspended by supporting cables that run along two towers located in between two anchorages. The tension from the deck travels from the cables, dissipates through the towers, passes through the anchorages, and finally absorbed by the ground.
Cantilever – The cantilever bridge is like a mix between the beam and the truss. Only difference is that the triangular units counterbalance each other with the use of an arm in between. Among the most notable cantilever bridges are the Quebec Bridge and Forth Bridge.
Cable-Stayed – The cable-stayed bridge is very similar to the suspension bridge in design in such a way that the deck is supported by cables. The only difference between these two types of bridges is that in the cable-stayed bridge only one tower is needed.
Tied-arch – The tied-arch bridge is immediately recognized with a large arch that rises from the bridge’s deck. Because this particular design transfers the tension into the deck of the bridge rather than on the ground, it is often used in areas where the soil isn’t as stable.
Box Girder – Bridges made from box girders are most popular for its torsional stiffness. It is often used in constructing highways and railway bridges. Box girders can be made from concrete (open top) or steel (orthrotropic deck).
Bascule – The most famous example of a bascule bridge is probably the Tower Bridge in London. Essentially, a bascule bridge is a drawbridge wherein counterweights sink into the water to lift the panels of the bridge open to let ships and boats pass.
Double-decked – As implied by the name, double-decked bridges have two decks or beams. One of the decks is usually used solely for vehicular traffic, while the other is used for pedestrian traffic.
Viaduct – A viaduct is a number of bridges that are connected together to form a longer structure.
The Most Famous Bridges
San Francisco Bridge – You’ve never been to San Francisco if you’ve never been to the San Francisco Bridge. It’s also the best example of a suspension bridge.
Tower Bridge – One of London’s landmarks, the Tower Bridge spans across the River Thames right near the Tower of London. It’s an example of a Bascule bridge.
Sundial Bridge – Designed by renowned Spanish architect Santiago Calatrava, the deck of this cable-stayed bridge is nonskid glass panels. This way the pedestrians will have the awareness of walking across the Sacramento River.
The Langkawi Sky Bridge – True to its name the Langkawi Sky Bridge is up in the skies. Located above the tops of Mount Mat Cincang in Malaysia, tourists who want to cross the bridge would have to ride a cable car to the top.
Hangzhou Bay Bridge – China’s Hangzhou Bay Bridge holds the record for the longest ocean-crossing bridge in the world.
These are the most commonly recognized types of bridges out there. Let me know if I’ve forgotten your favorite.