Understanding Culvert Shapes: Their Benefits & Limitations

A culvert’s shape isn’t just an aesthetic choice. The shape of a culvert can impact both structural and hydraulic performance.?

Each shape has its benefits and drawbacks, all of which should be considered throughout the design phase to ensure that the culvert performs as you need it to.

There are five common culvert shapes:

• Round Pipe Culverts
• Arch Culverts
• Elliptical Culverts
• Box Culverts
• Bridge Culverts

Round Pipe Culverts

By far the most common culvert shape, pipe culverts are popular because they’re easy to install and are competitively priced. They’re often the first and best choice for culvert designs.?

Engineers can use more than one pipe culvert in a project, allowing them to adjust for higher hydraulic loads while retaining the same headway.?

Additionally, pipe culverts offer a number of advantages:

• With a proper mix of design, thickness, reinforcement, and coatings, pipe culverts are applicable in a wide variety of hydraulic and structural scenarios
• Round culverts are one of the most cost-effective culvert shapes
• Pipes can be designed and installed to withhold tensile and compressive stress

Arch and Elliptical Culverts

Arch and elliptical-shaped culverts are often used in lieu of round culverts when engineers have low-flow hydraulic problems or limited headroom.

These culverts are among the most aesthetic options available to engineers and city planners. They’re also cost-effective, especially compared to box culverts.

As low-profile culverts, these designs maintain the waterway’s natural bed, enabling aquatic life

easy passage.

● Cost savings

● Faster construction times

● Greater hydraulic capacity

Box Culverts

Box culverts can withstand more punishment than other shapes. Their main selling points are their durability, functionality, and ease of installation.

Engineers can design a culvert system with a single box culvert or multiple, offering the opportunity to increase hydraulic capacity. This makes them ideal for bridging waterways and similar applications.?

Additionally, box culverts also offer

• A rigid frame capable of offering higher structural loads while simplifying the rest of the construction process
• The bottom slab of the culvert often reduces pressures on the surrounding soil
• Simplified construction
• Multiple construction options: cast-in-place concrete, precast concrete, and metal options are available.

Box culverts require extensive excavation. Over time, they can experience foundation problems, making them less useful in environments with shifting soil conditions.?

Bridge Culverts

While not very common, bridge culverts provide a unique combination of culvert and bridge. This has particular use cases–like when spanning a smaller waterway.?

A bridge culvert offers the same structural integrity as box culverts, with the added benefit of higher hydraulic capacity.?

Designing a Culvert? InfraSteel Can Help

InfraSteel offers engineers a variety of shapes to work with as each liner is manufactured to match the match the exact shape of the existing culvert. If you’re designing or rehabilitating a culvert, contact the team at InfraSteel to learn how we can help.?