NATM Tunnel

The NATM Tunnel of Panama Metro Line 3 is a key infrastructure element within the development of Panama’s future monorail network. This section marks the beginning of the transition from the elevated alignment to the main tunnel that will pass beneath the Panama Canal, providing the structural connection between the elevated viaduct and the underground railway through a technically demanding engineering solution. The works were executed using the New Austrian Tunnelling Method (NATM), a construction technique that allows the tunnel support system to be continuously adapted to the geotechnical conditions encountered during excavation, thereby optimizing the structural behaviour of the tunnel

From a structural engineering perspective, the project comprised the construction of the reinforced concrete invert slab, portal structures, tunnel arch and structural slabs, forming the cut-and-cover transition structure that connects the elevated alignment with the main underground tunnel. The complex geometry of these structural components required a high level of coordination between reinforcement detailing, fabrication and concrete placement to ensure structural continuity and compliance with the demanding requirements of the railway system

ERSIGROUP was responsible for the supply, cutting, bending and fabrication of approximately 820 tonnes of reinforcing steel for all the tunnel’s structural elements. Through its industrialized reinforcement fabrication processes, ERSIGROUP optimized manufacturing efficiency, reduced on-site installation time and achieved a high level of dimensional accuracy for every reinforcement assembly. The integration of detailed engineering, industrial production and specialized logistics enabled ERSIGROUP to maintain a continuous supply of reinforcement in line with the construction programme while ensuring the highest standards of quality, material traceability and production control throughout every stage of the project

ERSIGROUP‘s extensive experience in fabricated reinforcing steel solutions for railway tunnels and underground structures was once again demonstrated in this project, delivering industrialized reinforcement solutions for a key section of Panama Metro Line 3 and reinforcing the company’s expertise in major reinforced concrete transportation infrastructure

KEY MILESTONES

• Transition structure connecting the elevated viaduct with the main tunnel beneath the Panama Canal
• Constructed using the New Austrian Tunnelling Method (NATM)
• Reinforced concrete construction including the invert slab, portal structures, tunnel arch and structural slabs
• 820 tonnes of fabricated reinforcing steel produced using industrialized manufacturing processes
• Reinforcement supply, cutting, bending and fabrication carried out by ERSIGROUP
• High-precision reinforcement assemblies for complex underground reinforced concrete structures
• Implementation of advanced detailed engineering, industrial fabrication and logistics processes by ERSIGROUP, optimizing productivity, dimensional accuracy, full material traceability and quality throughout the execution of the project