Beam bridge designs are a cost-effective, simple design that works well for several landscapes. A beam bridge, or stringer bridge, is composed of beam members that make up the bridge’s superstructure and work best for short span lengths.
Once you understand what are the strengths of a beam bridge and its pros and cons, you will be able to determine if it’s the best bridge design for your project. Note, this article is intended as a basic orientation and not a structural design guide.
What are the Strengths of a Beam Bridge Structurally?
By understanding what are the strengths of a beam bridge will help you to determine if it’s the right bridge design for your project.
FRP beam bridges have a simple structural form that:
- Is typically less than 30 feet.
- Contains horizontal beams.
- Is supported by abutments at each end of the bridge.
The weight from walkers, bikers, or lightweight vehicles is transferred onto the horizontal members, which causes compressive forces in the beam’s top flange while the bottom flange is in tension.
Beam Bridge – Strengths
Now that you understand how forces are distributed in a beam bridge, here are some benefits to building a pedestrian beam bridge.
Due to their simple design, beam bridges are very cost-effective to build and assemble, which helps to save on design and construction costs.
#2 Select from Several Material Options
Beam bridges can be constructed with several different materials to meet design requirements and budget constraints.
- Fiber reinforced polymer (FRP)
#3 Faster Construction Time
The simple design makes assembly easy. If it’s hard to access the site, steel bridge parts can be difficult to transport. At the same time, FRP parts are more lightweight and can be easier to transport to remote locations.
#4 Functional in Many Locations
The beam bridge design works well in various locations from nature trails, national parks, community spaces, and even personal homes.
#5 Several Design Options
For a beam bridge, you can choose from several design options for the bridge’s appearance, including:
- Built-up shapes
- Decorative curb and handrail options can be added for aesthetics and/or safety
Beam Bridge – Weaknesses
Just like with all bridge designs, there are some disadvantages to building a beam bridge, depending on your project needs.
#1 Limited Spans
There is a direct correlation between the possible length of the bridge and the depth of the beam. Therefore longer spans require a deeper beam which may impact the abutment design and aesthetic qualities of the bridge. Beam bridges, then, tend to be better for shorter spans.
#2 Potentially Lower Aesthetic Value
A standard beam bridge has a very simple linear design. Depending on the location and type of installation a truss bridge may add more aesthetic value to a site.
Is a Beam Bridge Right for You?
If a beam bridge is the best design option for your project, contact the Areté Structures team. Our team will work with you throughout the planning, design, and assembling process.