With 60 years’ experience in the field of underground structures, SYSTRA has the advanced skills required to provide innovative solutions for tunnel design and construction, supporting clients on their most challenging projects.

Overcoming underground construction challenges

Densely populated areas, topographical challenges and limited space are making underground road and rail solutions increasingly attractive – especially in urban areas. Tunnels offer an effective, safe and sustainable way to help reduce congestion on major roads, extend public transport networks, and create new transport options for fast-growing populations.

Tunnels are complex structures requiring highly specialised expertise to navigate the challenges of geology, topography and congested underground environments. Specialist surveys, expert risk management and mitigation, and advanced design technologies are required to deliver successful tunnel engineering projects.

SYSTRA has six decades of experience in designing and rehabilitating underground structures, especially railway stations, road and rail tunnels around the world. We understand how to optimise the use of underground spaces, particularly in difficult geological environments and sensitive built-up areas.

Discover how SYSTRA has applied innovation, technology and ingenuity to re-think infrastructure engineering solutions to optimise time, budget, safety and sustainability.

SYSTRA provides specialised tunnel engineering services to solve the extraordinary challenges of building new underground infrastructure – ensuring we optimise clients’ operating and maintenance performance, while reducing costs and delivery times.

SYSTRA has designed and built underground structures all over the world in the most demanding conditions – whether crossing dense urban areas, mountains or the sea. We know how to design and engineer all types of underground structure, with expertise in designing and supervising deep excavations in any geological or geotechnical context.

Managing risks in tunnel design

Risk management is at the centre of tunnel design. Our tunnel engineers help to develop proper risk matrices and identify the most suitable mitigation solutions for each project. We systematically integrate the most advanced technologies to assess and mitigate all possible risks linked to tunnelling projects.

Our ability to model the complex interaction between the ground and structures enables us to develop customised solutions for every tunnelling project. We have experience of tunnel engineering in geological settings and climates across the world. Our engineers rely on interactive and geo-referenced platforms to manage and model ground data and the surrounding built environment. Geotechnical data from SYSTRA projects all around the world is stored and shared in the GIS web-application GEOShare.


  • Design – geotechnical studies; feasibility studies; concept, preliminary and detailed design; architecture and landscape design.
  • BIM modelling – civil works; road and terrain; finishes and MEPs.
  • MEP design – safety system design; ventilation and fire safety; CFD simulation.
  • Value engineering – project optimisation; asset management; new technology implementation.
  • Project management – project planning, monitoring and risk assessment.
  • Construction management – construction planning, design, monitoring and risk assessment.
  • Tender assistance – communication strategy; graphics support; schematics and renderings; illustrative videos.
  • Independent checking – code compliance; technical content; project buildability.
  • Structural assessment and repair – structural assessment; condition evaluation and inspection; repair works; rehabilitation.

Innovative techniques for underground construction

Successful underground projects rely on selecting the most appropriate construction methods. We offer design solutions for all types of underground structure, from machine-bored tunnels to NATM (drill & blast) tunnels and cut-and-cover tunnels, in any kind of soil or rock.

Through our many years of experience in tunnel engineering, we have developed many innovative underground solutions. These include smart cross-passage excavation techniques, advanced fire safety engineering, fibre-reinforced concrete (FRC) precast linings, and the use of expanded soft clay for backfilling.

Worldwide tunnel engineering projects

SYSTRA has been involved in major tunnel projects worldwide, such as the Tunnel Euralpin Lyon-Turin, the Ismailia twin-tube road tunnel under the Suez Canal, the Mont Blanc tunnel renovation, and the largest underground rail project in Europe: the Grand Paris Express in the Paris region.

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18 August 2023

Reinforcing tunnelling expertise with Bamser & Subterra acquisitions

SYSTRA strengthens its expertise in tunnelling with the acquisition of two specialist companies, Bamser in Australia and Subterra in Spain.
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Sustainability at SYSTRA

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Find out what its like to work at SYSTRA, rewards, benefits and about different career pathways including apprenticeships and graduate opportunities.