10/3/2025
Infrastructural Precasting: Optimising the Production of Tunnel Segments
In the field of large-scale infrastructure, the production of prefabricated tunnel segments must meet extremely high technical standards.
The internal reinforcement plays a decisive role: the reliability of the entire structure depends on it.
Traditional reinforcement manufacturing methods, often artisanal and fragmented, present significant limitations in terms of productivity, quality control, and safety.
The complexity of internal reinforcement, combined with the need to guarantee quality, efficiency, and continuous production, makes it essential to rethink conventional methods.
This is why automating and industrialising the process has become a necessity.
TNL fits precisely into this framework: an automated plant for the production of electro-welded reinforcement cages for tunnel segments.
In the field of infrastructural precasting, tunnel construction is one of the most demanding challenges.
Precast segments used in tunnel linings are subject to extremely stringent requirements for strength, durability, and geometric accuracy.
The internal reinforcement plays a decisive role in guaranteeing the overall reliability and performance of the structure.
The Challenges of Traditional Production
Tunnel segments are typically reinforced using three main methods:
- Steel fibres: This method does not require dedicated reinforcement cages or specialised production lines. However, it offers limited mechanical performance and is therefore rarely used in projects with specific structural requirements.
- Stirrups and rebars: In this case, reinforcement is manually assembled by placing loose bars onto templates. This method requires a high amount of manual labour, results in low productivity, and carries a high risk of quality variation due to potential errors or inaccuracies during cutting and bending.
- Electro-welded elements: This solution significantly reduces the number of components to be assembled and speeds up the installation process, resulting in greater consistency. However, this production method must comply with very strict quality standards—both in terms of structural precision and weld strength—since prefabricated cages are rigid and cannot be adjusted or reshaped during assembly.
TNL: Efficiency, Precision, and Certified Welding
TNL, the plant developed by AWM – Schnell Group, represents a true revolution for manufacturers in the sector.
It is one of the most advanced automated solutions for the production of electro-welded reinforcement cages for precast tunnel segments.
It ensures:
- Geometric precision, through mechanical centring systems and automatic wire positioning devices;
- High welding quality, thanks to continuous monitoring of welding parameters;
- Reduced labour requirements, a single plant can replace up to 20 welders per shift;
- Increased productivity, due to a continuous and consistent production cycle;
- Fully automated operations, minimising reliance on specialised operators.
Faster Production, Fewer Errors
With TNL, reinforcement production for tunnel segments transforms from a manual, complex, and unpredictable process into a streamlined, automated industrial system, ensuring consistent quality and reliable delivery times.
It’s a strategic investment for precasters in the infrastructure sector who want to take on large-scale projects with efficiency, precision, and full compliance with demanding technical standards.
