Durable and efficient solutions for underground tunnels

Tunnel pipes are an essential solution for underground passageways, offering a highly durable and efficient structure for various infrastructure applications. These tunnel pipes are widely used in drainage, pedestrian underpasses, and buried tunnel systems, ensuring high load-bearing capacity while maintaining structural integrity. Their optimized design allows for easy installation, cost-effectiveness, and long-term reliability.

Reduced maintenance costs

Our tunnel pipes offer a set-in-place construction process, eliminating the need for extensive formwork or scaffolding. Installation is highly efficient, with around 10-15 elements (12 meters) assembled per day. Compared to traditional on-site cast tunnels, which may take months to complete, a tunnel pipe system can be fully installed in just a few weeks, significantly reducing construction time and associated costs.

Optimal shape

The tunnel pipe design features a cross-section that enhances both structural efficiency and hydraulic performance. The curved geometry improves load distribution while allowing for better water flow management and clearance optimization.

Customizable design

In addition to the standard tunnel pipe structures, customization options such as footings, headwalls, and wingwalls are available to meet specific project requirements. These enhancements provide greater versatility in underground infrastructure planning.

Fast and simple installation

Tunnel pipes are designed for rapid and hassle-free assembly. The set-in-place system enables swift construction with minimal labor requirements. Approximately 20-25 meters of tunnel can be installed within 2-4 weeks, drastically reducing project timelines compared to traditional cast-in-place solutions.

Minimal social disturbance

The quick installation process of tunnel pipe systems reduces the need for long road closures and minimizes disruptions to traffic and surrounding environments. The streamlined construction approach helps decrease accident risks while ensuring a safer and more efficient urban infrastructure.

Environmentally friendly

Tunnel pipes contribute to sustainable construction practices by utilizing locally sourced backfill materials, such as on-site gravel, reducing the need for excess transportation. Additionally, when used in drainage applications, the three-sided design allows for natural streambed preservation, enabling unobstructed aquatic life movement and reducing environmental impact.

Pedestrian Tunnels and Underpasses: Safe Crossing Solutions for Roads and Railways

ViaCon Tunnel Pipe systems provide grade-separated pedestrian and cyclist crossings beneath roads, railways and other infrastructure corridors. Manufactured from corrugated steel with diameters ranging from 1.5 to 6 metres, these structures offer a safe, well-lit passage that eliminates the need for at-grade crossings — reducing pedestrian-vehicle conflict and improving accessibility for communities bisected by busy transport routes.

Every Tunnel Pipe installation is designed to the relevant loading standards, including DMRB CD 354 for highway loading and Network Rail standards (NR/L2/CIV/030) for railway crossings. The corrugated steel shell provides inherent structural strength while accommodating ground movements and differential settlement. Internal finishes include anti-graffiti coatings, integrated lighting systems and non-slip floor surfaces to create a safe, welcoming environment for users. ViaCon’s engineering team provides full design, specification and installation supervision for pedestrian tunnel projects across the UK.

Wildlife Underpasses and Ecological Crossing Structures

Tunnel Pipe structures are increasingly specified as wildlife underpasses — enabling safe passage for mammals, amphibians and reptiles beneath roads and railways. Badger tunnels, otter crossings and general fauna passages are designed in accordance with DMRB LD 118 (Biodiversity Design) and Natural England’s standing advice on protected species. ViaCon supplies dedicated wildlife crossing structures with natural substrate floors, open mesh ends and mammal-friendly dimensions that encourage regular use.

For larger ecological crossings — such as deer passages and combined pedestrian-wildlife routes — ViaPlate multi-plate structures provide spans of up to 25 metres with natural earth floors and vegetation on the approach embankments. Combined with HelCor pipe culverts for watercourse crossings, ViaCon offers a complete range of ecological crossing solutions for transport infrastructure projects.

Tunnel Pipe Specification and Installation

ViaCon Tunnel Pipe is manufactured from corrugated galvanised steel plate, assembled from bolted segments on site. Standard corrosion protection is hot-dip galvanising to BS EN ISO 1461, with optional polymer coating (Trenchcoat®) for extended design life in aggressive environments. The corrugated profile provides high ring stiffness at low steel thicknesses, enabling cost-effective structures with shallow cover depths — an important advantage on constrained urban sites where conventional cut-and-cover tunnelling is impractical.

Installation methods include traditional open-cut construction (excavate, place, backfill) and jacked installation for crossings beneath live railways and highways where disruption must be minimised. ViaCon’s project team coordinates design, manufacturing, delivery and installation supervision to ensure each tunnel pipe meets its structural, hydraulic and operational performance requirements.

Applications:

  • Bridges
  • Overpasses
  • Pedestrian tunnels
  • Ecological crossings
  • Underpasses

Steel: The smarter choice

The strength and sustainability of steel provides durability and lifespan advantages for construction projects.

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Value engineering

With consultative problem solving and the versatility of steel, value engineering ensures adaptable, cost-effective solutions.

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Case studies

Discover the full range of real-world implementations and sustainability benefits of ViaCon solutions and expertise.

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Welcome to the ViaCon design toolkit

We have put together a selection of useful tools, calculators, information and downloadable resources to help you find what you need quickly and get the most out of your ViaCon system.

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A Tunnel Pipe is a highly durable and efficient pre-fabricated structure used to create underground passageways. It is engineered to handle high loads while maintaining structural integrity, making it an ideal solution for applications like drainage systems, pedestrian tunnels, and ecological crossings.

Tunnel Pipes offer several significant advantages over traditional construction methods:

  • Fast installation: A system can be installed in just a few weeks, compared to months for on-site cast tunnels, drastically reducing project timelines.

  • Cost-effectiveness: The rapid, set-in-place installation process reduces construction time, labor needs, and associated costs.

  • Minimal disruption: Quick construction minimizes the need for long road closures, reducing disturbances to traffic and the local community.

  • Durability: The optimized curved shape enhances load distribution and structural efficiency, ensuring long-term reliability with low maintenance costs.

The installation process is exceptionally fast. Approximately 10-15 elements can be assembled per day, allowing for 20-25 meters of tunnel to be fully installed within just 2-4 weeks. This is a significant time-saving compared to traditional cast-in-place methods.

They support sustainable construction in two key ways:

  1. Reduced transportation: They are designed to be used with locally sourced backfill materials (like on-site gravel), which minimizes transport emissions.

  2. Habitat preservation: When used for drainage, the three-sided design allows for the preservation of the natural streambed, enabling fish and other aquatic life to move without obstruction.

Yes. In addition to the standard structures, we offer customization options such as footings, headwalls, and wingwalls to ensure the solution meets your project’s specific requirements and integrates perfectly with the surrounding infrastructure.

Tunnel Pipes are versatile and can be used for a variety of infrastructure projects, including:

  • Bridges and Underpasses

  • Overpasses

  • Pedestrian Tunnels

  • Ecological Crossings (Wildlife Passages)

  • Drainage Culverts

Pedestrian underpasses are typically constructed using the open-cut method: a trench is excavated, the corrugated steel tunnel sections are assembled in the trench, structural backfill is compacted around and over the structure, and the road or railway surface is reinstated. For crossings beneath live railways or busy highways, jacked installation can be used — the assembled tunnel is pushed horizontally through the ground using hydraulic jacks, avoiding the need to close the route above. ViaCon provides full design and installation supervision for both methods.

A wildlife underpass is a purpose-built crossing structure that enables animals to pass safely beneath roads and railways, reducing wildlife-vehicle collisions and maintaining ecological connectivity. ViaCon wildlife underpasses are designed with natural substrate floors (earth, gravel or vegetation), open sightlines and dimensions appropriate to the target species — from 600mm diameter badger tunnels to 6m+ span deer and multi-species passages. Design follows DMRB LD 118 (Biodiversity Design) and Natural England guidance on protected species mitigation.