Throughout history, there have been a number of bridge designs that have stood the test of time. They have served an important role in the development of civilization, the movement of trade and troops and even the spread of knowledge around the world. The basic design of most bridges has not changed throughout the centuries. But there have been some amazing designs that have been constructed in the past several hundred years. For your curiosity, here are the types of bridges that have defined history and modernized infrastructure around the world. There are many types and styles that have been invented throughout the ages. Many of them are still around today and some are still being used.
Table of Contents
- Looking at Structural Bridges
- Moving On To Fixed and Moveable Bridge Types
- How Each One Can be Used
- Other Types of Bridges
Looking at Structural Bridges
Every type of bridge is an amazing feat of engineering. The ability to construct a pathway that has the ability to hold up to various obstacles is spectacular. Bridges must be able to handle a wide range of weighted loads, extend for miles and move with the elements. Every piece of bridge design is important. For cable bridges it matters where the cable is placed and in what shape. The elements that fight against bridge construction can also be distributed evenly by how the trusses are placed. All the design and science of bridge matters to how it handles things.
The basic science behind the bridge construction is fairly straight-forward. The fact is that the structure of the bridge will dictate how the bridge will handle tension, compression, torsion, sheering, and bending. Each construction style is made to handle all or more of the elements that it must withstand. All bridges handle the same elements, but some are able to handle a greater percentage of them based on their construction.
Classic Arch Bridges
The arch bridge is one of the oldest designs of bridges around. One of the most famous arch construction is the Caesarea Aqueduct. This construction clearly uses the arch design for support. Its main function was to transport water across a large section of land. The arch is always located underneath the load that it is trying to support. In the early days of their construction, they would have been built using stone and dirt. When packed together the arch design becomes one of the strongest bridges ever constructed. Many bridges today use the same style to facilitate heavy loads. Some of the types that are built include train bridges and aqueduct construction.
This design is perfect for pedestrian traffic, railcar, motorized vehicles, and as the picture shows the transportation of water. This type of bridge can be made out of any type of material. Each section of the design has to be built similar to its corresponding side for it to work properly. The arch bridge is seen in just about every culture around the world that had the technology and ability to build such awesome structures.
The oldest bridge in the world that can be dated and is still in use is the slab-stone single-arch bridge. This bridge stretches of the river Meles in Turkey. The bridges have a date of 850 BC. It is a part of the Mycenaean bridges that still exist today. This bridge shows how powerful and strong the arch bridge can be as it stands the test of time.
Simple Beam Bridge Design
Beam bridges are the oldest known form of bridge construction. Beams are placed in a horizontal fashion either on piers or some form of the abutment. In the early days of this construction, humans would use wooden piers to support the beams. Once these pieces were in place material would be used to create the walkway of the bridge. Over the years the form of the bridge has taken on different looks. They can be built now as girder style bridges, plate bridges, box bridges, and the simplest form beam bridges. The bridge that spans Lake Pontchartrain Causeway is a perfect example of this type of bridge.
There are two forms of a truss bridge that can be constructed. The first is what is known as a king post. This type of design uses two posts positioned in a diagonal position that is supported by a vertical post at the center. The second form is the queen post which uses two diagonal and two vertical posts that are connected by a horizontally placed post. This design of the bridge can handle loads that extremely heavy because its design spreads the weight of the load out over the bridge.
There are many types of truss designs that can be used for construction. They are the Allan, Bailey, Baltimore, Bollman, Bowstring, Brown, Howe, Lattice, Lenticular, Pennsylvania, Pratt and many other designs. One of the most interesting construction types is Pratt. This type of design was used extensively during World War II. The creator of this design was Thomas Willis Pratt and his father Caleb Pratt. This bridge design ca span large distances and is easily set up. Its ease would entice people around the world to build the Pratt bridge design.
The Cantilever Bridge
The most famous cantilever bridge is the Quebec Bridge located in Canada. The Quebec Bridge is the world’s longest cantilever design. It has a length of 549 meters at the center of the bridges. Its overall length is 987 meters. It was opened to use in 1919. Its design allows three lanes of traffic, a rail line, and a pedestrian lane to cross the river.
This bridge style is very similar to an arch, but the support of the load is done through the diagonal placing of the beams. In order for this bridge to span great distances, it must be supported by piers or solid foundations. Because of the design longer distances are avoided because of the complexity of the design. The design can utilize truss formation above or below the main bridge pathway. These bridges are typically made from steel, iron, and concrete.
Tied Arch Bridges
This style of bridge is similar in design to the ordinary arch bridge. The main difference is that the weight is transferred to the top chord and is ultimately connected to the bottom cord in the build of the structure. Some other names of this style are bowstring arches or bowstring bridges. They can be built in a wide array of fashion such as:
- Shouldered tied arch.
- Multi-span discrete tied arches.
- Multi-span continuous tied arches.
- Single tied arch per span.
These bridges are a treat to look at, but they are very costly to maintain. A perfect picture of this type of bridge is the Gateway Bridge that links the upper and lower parts of Michigan. The structure is 250 feet long and wide enough for multiple lanes of traffic.
Suspension Bridge Model
A suspension bridge is a design that uses ropes or cables to support the weight of the bridge. All the weight of traffic and pedestrian crossing is supported by the cables that are connected to its vertical suspenders. This type of bridge is a preferred choice of construction for areas with high winds, prone to earthquakes and vibrations from the amount of traffic that will flow across it. Of all the bridges of this design, the Golden Gate Bridge in San Francisco is the most notable. This bridge has withstood countless earthquakes. It is designed to sway as the vibrations pass through the structure. When the California earthquake hit the area of San Francisco in 1989, the Golden Gate Bridge swayed in the wind. It was determined that no real damage had affected its structure. It was designed to withstand those kinds of disasters.
The Historical Cable-Stayed Bridges
This type of bridge has its roots back in the 16th Century. This type of bridge will use cables that are connected to pylons. Usually, the pylons are found in the center of the bridge and other key support areas. These cables are connected to the pylons in one of two ways. The first is called the harp design. The cables are attached to the pylon in different areas. The second way is called fan design. With this design, all the cables will meet at one point near the top of the pylon. These bridges are made to span long distances. They can be made out of any material and can support every type of decking that is currently sold and used on the market.
The longest cable-stayed bridge in the world is the Russky Bridge located in Vladivostok. It span reaches over 3,100 meters. It carries just about every type of vehicle and cargo transported on road and rail. It is made up of steel rope, concrete box girders, steel, and concrete pylons. It is the perfect example of the cable-stayed bridge design.
Moving On To Fixed and Moveable Bridge Types
It should not surprise anyone that most of the bridges in the world cannot be moved. They sit there until they are destroyed or collapse because of age. There are some bridges of the world that are moveable in one fashion or another because of the reason why they are built or their location.
Understanding a Fixed Bridge
This type of construction features absolutely no moveable parts. There are no gears or engines that can be powered to move the bridge in any given direction. Their purpose is to allow passage of cargo and people over stretches of land or water that would have been impossible without the bridge. They are made of all types of material. But history has shown that bridges made of earth and stone are going to last longer than those of steel and other material unless they are maintained and refurbished over time.
The Temporary Bridge
This type of bridge has a short life span. They are usually constructed of light and durable material. Heavy loads are usually broken down into lighter loads because they cannot handle a lot of weight. A temporary bridge is usually set up to allow for the construction of more permanent structures. Many construction companies will erect temporary bridges to facilitate traffic movements and the transportation of material to a job site. Once the use bridge is no longer needed it is taken down.
The Moveable Bridge
This bridge type is one of the most fascinating bridges that is constructed today. They must be built to withstand heavy loads and be able to be moved when it is necessary. The function of this type of bridge is to allow safe passage of multiple types of loads. But they are supposed to be able to move out of the way when large ships need to float under them.
The Illinois river has a lot of moveable bridges built over it as it traverses through Chicago. These bridges are designed to raise up and turn to the side to allow boat traffic to flow in and out of Lake Michigan. Some of the bridges have two parts that will raise up out of the way to allow the boats to pass underneath.
When a boat approaches the bridge they are to slow down and come to a stop. Usually, the boat owner anchors off and contacts the bridge control tower asking for permission to pass under the bridge. Some of the bridges are designed to raise and lower at set times of the day. But usually, the bridge operator will wait until there are several vessels that need to pass before raising the bridge.
How Each One Can be Used
Every bridge has at least one function. Many though have been built to facilitate multiple usage options. Some of them have been built to allow cars, people and bikes, and even rail to pass over the same spot. High-tech engineering has been used to build these bridges. They are designed to serve a purpose in an area of the country that sees a lot of the same kind of traffic.
The Pedestrian Bridge
This type of bridge dates back to early construction times. A local tribe or village would have a need for an easy way to pass over a ravine or body of water, so they would build a footbridge. Modern-day pedestrian bridges can be built and decorated in a wide array of fashions. Many times, local city ordinance will dictate what the bridge should look like and what color it is to be painted.
Many of the pedestrian bridges that crossover dangerous areas will have fencing or protecting barriers to keep people from harm as they pass over. The most common of these bridges will have a stairwell that leads up to the main walkway. From there the person will be able to crossover with no problems. Some cities have utilized the bridge construction into what are called skywalks. This type of construction keeps people out of the weather. They usually connect buildings together so people do not have to pass through traffic to reach their destinations.
Cars and More Cars
Traffic is very frustrating to people. No one likes to sit in an area longer than a few minutes in their car. This thought is taken into account when traffic bridges are designed and built. There are multiple types that can be constructed.
Single Story Construction
This type of vehicle bridge is the most common. It can be constructed using any of the construction styles. Most of the time there are multiple lanes that travel side by side allowing cars to pass and speed along at fast paces. The longest of this type of bridge is the Manchac Swamp Bridge that makes it way through Louisiana. It has a length of 22.8 miles which makes it the longest in the world over water. The bridge is constructed in sections that allow for easy repair as sections of it wear out over time. The pylons of the bridge were driven down to a depth of 250 feet to help stabilize the bridge.
Double Decked Bridges
This type of bridge is used in large cities that have a limited amount of space to move its traffic. One row is cars that are allowed to essentially drive on top of the other row. This construction type creates a tunnel for one way of traffic while the other way is out in the open. This is the style of the bridge that collapsed in 1989 after the California earthquake. The Cypress Street Viaduct was a double-deck roadway. That earthquake was felt over 300 miles south in the central parts of the state.
The Train Bridge
This bridge type is perhaps one of the strongest ever built. It can be built to allow one train to pass or multiple trains at one time. They can be built under-car bridges and even with pedestrian traffic bridges. These types of bridges have their beginnings during the industrial revolution in Europe. People began looking for better ways to transport their goods. The rail was the most common way so bridges were built so the trains could get around more easily. The arch construction type is the most commonly seen. The archway is able to handle extreme weight loads without collapsing. These bridges can be constructed in a wide range of styles and types. One of the common ways for this bridge to function is to build under or next to traffic bridges. They are small enough to pass under the bridge without having to change much of the design.
Other Types of Bridges
The pipeline bridge is rarely seen as a stand-alone bridge. Usually, the pipes are attached to the side of an existing bridge. But where there is no bridge a pipeline bridge can be easily built. These bridges are constructed for the largest of all pipes. They can be built easily by pylons and then running the pipes on top of the pylons. In some cases, the pipes themselves become the bridge. This is done when the distance to cover is relatively short. This is usually seen when a roadway must pass over the pipeline. It is easier to bend the pipe than it is to build a bridge over the pipes.
The aqueduct bridge has been used for centuries to transport water to cities and other places. The arch type is the most common form of ancient days. But today’s construction allows people to be a little more creative with the design. But the more simple design using the arch structure, and they are usually made of stone. The bridge would be built along ridgelines and would twist and turn through the area until it made its way to the city. Most of the ones built today are done with pipes and pylons.
Commercial Bridges are used to house restaurants and shops. Foot traffic is usually what is found using the bridges as the people enjoy the business on them. This is clearly seen on the bridge of Slovakia city of Bratislava. This bridge allows traffic to flow over the ravine while at the very top a restaurant is positioned so people can enjoy the view of the city. In most cases, this type of construction is used to enhance tourism and curiosity.