Underground works

For almost 10 years, Sofren has been bringing you its expertise in the design and construction of tunnels, viaducts and other underground structures.


These projects often present real challenges and have high requirements in terms of engineering. As these types of structure are in urban environments with complex phasing, or in the middle of the countryside in environments that are not conducive to building major structures, technological choices and construction methods are vital.

Most structures are vaults, tunnels, car parks for new or existing infrastructure (which requires managing the construction or renovation works alongside the operation of the existing infrastructure). Sofren’s teams also conduct studies on modifications to structures, in particular for railway stations that need to upgrade for people with disabilities, incorporating buried structures on platforms in operation. We produce studies on railway routes, including geotechnical and hydraulic issues. Consequently, work on a simple footbridge located in a very busy station and with no possibility of interrupting rail traffic during the "work" phase may be critical.

Sofren now believes that the transport and water sectors will be facing very significant challenges over the next 50 years. In both areas, building tunnels and bridges will have a particularly important role to play, whether they link cities, or reduce rural isolation. As regards transporting water and anything relating to sanitation services, developed and developing countries would all like to improve the quality of their water as well as their supply systems and wastewater networks.

Sofren’s range of services therefore includes:

  • In relation to the technical aspects, civil engineering, geotechnics taking into consideration innovative foundation systems, diagnostics of structures, hydraulic studies, etc.
  • In relation to the organizational aspects: project and overall project planning methods, quality systems.


Sofren is able to work on every aspect from the feasibility phase to the operating and maintenance phase including evaluation and design, construction methods, supervision of works and renovations. Sofren also has recognized expertise in responding to calls for tenders.

Through the close partnerships it enjoys in this industry, Sofren has developed expertise in relation to the safety, ventilation, and operation of tunnels, signalling and integrated systems. Thus, based on operating income, Sofren is able to offer the different disciplines required for tunnels or bridges to its partners.