What is a Beam Bridge?
The beam bridge is an important architectural development.
The beam bridge is the simplest and oldest type of bridge. A girder bridge or stringerbridge is another name for it. It usually consists of one or more spans supported at each end by an abutment or pier.
Why are Beam Bridges Important?
They may have once taken the form of a log over a stream, but we are more familiar with them now as enormous box steel girder bridges. A beam bridge can be made of a variety of materials, including hardwood planks, stone slabs, reinforced concrete, or steel.
What are Beam Bridges made of?
A beam bridge is made consisting of a horizontal rigid framework (a beam) and two supports, one at each end, on which it rests. These components directly support the bridge’s downward weight as well as any vehicles passing beneath it. The bridge becomes continuous when two or more beams are securely linked together over supports.
A beam bridge must be strong. It must be able to withstand twisting and bending when loaded. A beam bridge’s deck is usually built of reinforced concrete or metal.
The distance that a beam can span is determined by the size of the beam and, in particular, the height of the beam. For beam bridges with short spans, wide flange rolled form beam bridges are usually the most cost-effective style of beam construction.
Beam bridges come in a variety of shapes and sizes. Many beams side by side with a deck over the top, to the main beam either side supporting a deck between them, are examples of construction types. I-beams (also known as H-beams), trusses, or box girders could be used as the main beams.
Many people criticize their design, while others admire it for its simplicity and attractiveness. Let’s look at some of the benefits and drawbacks of beam bridges.
Pros of a Beam Bridge
1. Ease of Construction
The design of beam bridges is regarded to be one of the most basic of all bridge types. The most basic style of Beam Bridge is made out of a single long beam that is supported at both ends by piers. To withstand the weight of the passenger flow that happens above, extended bridges adopting this design may need numerous piers.
2. Low-cost construction
Beam bridges are one of the most cost-effective ways to construct a bridge today. It’s a fantastic method to save money on key infrastructure while while maintaining design simplicity.
This benefit is why most communities consider it the top choice for connecting one location to another in any type of environment. These bridges can be a good replacement for arch and suspension bridges. A beam bridge is a type of bridge that is utilized in urban and rural locations where there is a lack of funds.
3.Improved Construction Time
In comparison to other types of bridges, the beam bridge usually takes less time to build. Because most modern beam bridges are made of a combination of steel and reinforced concrete, the construction process is quick. However, the size and location of the project play a role. Construction time may be extended in remote places where material delivery is a big issue.
4. Adaptable to Almost Any Situation
If you come across a bridge while strolling along a nature trail, it’s more likely to be a beam bridge. Despite the fact that some beam bridges perform better than others due to their placement, this design can be used in a range of settings.
It is the most frequent type of highway and railroad bridge. It can swiftly and effectively provide necessary support while also allowing traffic to flow beneath it on highways. This bridge design has been demonstrated to be useful on everything from walking trails to interstates.
5. A variety of design options
Beam bridges are made out of a single long beam that is supported at both ends by piers. A side-by-side beam configuration is used in most beam bridges, allowing the deck to rest on top of the supports.
The piers would be first, followed by the underlying supports, and finally the deck. This placement, combined with its simplicity, results in a bridge that may be used practically anyplace. H-beams, girders, and trusses can be used to regulate the horizontal stresses that the structure will face over time.
Cons of a Beam Bridge
1. The Bridge’s Length Is Limited
Because, unlike truss bridges, beam bridges have no built-in supports, they are often only employed for short distances. Because the beam bridge’s supports are often spaced far apart, it can be difficult for the bridge to maintain its structural integrity over time.
For modern weight requirements, a single span can hold around 100 meters of length with current technologies. Anything longer than that will necessitate the building of additional spans, which can be linked as needed to build a longer bridge.
2. Sagging Problems – Load Issues.
The sagging of the beam bridge is a prevalent issue. The loads on the bridge will generate a downward pull. As weight is added to the bridge’s load, this impact becomes more prominent.
Because there is no weight transfer on a beam bridge’s supporting structures, repetitive heavy weight on a single area might cause the bridge to droop. That is why certain weight restrictions are put on tiny bridges in rural areas.
3. Unappealing Aesthetics
The conventional beam bridge resembles a table in appearance. The deck is on top, the supports are below, and the piers hold the weight. Many people consider them to be the most boring of all bridge designs. Although simplicity and cost-effective construction are advantages, they are not always aesthetically beautiful. This design is not architecturally interesting because it resembles any other highway.
4. It Becomes Weaker With Time (Life Expectancy)
The typical lifespan of a beam bridge is 50 years or less. Beam bridges gradually deteriorate due to the wear and tear of bearing the deck’s weight. Even if the bridge is made of reinforced concrete and steel, a span with heavy traffic may have a rated lifespan of only 25 years. Beam bridges, on the other hand, will need to be replaced at some point.
5. It Isn’t Always Cost-Effective
From a cost aspect, beam bridges may be the most cost-effective design. Even for short periods, though, it can be costly.
Concrete is a low-cost material for beam bridges. Concrete, on the other hand, is not strong enough to withstand high tension forces on its own (pulling). Concrete must be reinforced with costly steel mesh, which raises the building cost.
