Underground works

WORLD-RENOWNED EXPERTISE IN TUNNEL DESIGN AND CONSTRUCTION

Our clients benefit from our recognised expertise in working all over the world on underground projects with more than 2,000 km of tunnels completed in the last 40 years, making us a key player in the sector. Our operational excellence is fuelled by global feedback from all our projects and by shared innovation programmes within VINCI Construction.

We also take a partnership approach with our clients to meet their unique needs and deliver projects that contribute to the development of sustainable territories and infrastructure, thanks to our experienced teams working in complex environments and our ability to develop tailor-made solutions.

THE CHOICE OF THE BEST BUILDING TECHNIQUE: TUNNEL BORING MACHINE OR CONVENTIONAL

We have developed specialised skills in all types of tunnelling, using both tunnel boring machines and conventional tunnels. We carry out tunnels from their desig, through construction, to their acceptance, regardless of their complexity.

Tunnel of the Rijnlandroute project in the Netherlands

We are experts in the use of tunnel boring machines and benefit from long-established relationships with the best specialist suppliers in the field. We are thus able to respond to the specific constraints of our clients’ projects. We master the prefabrication of the segments, whose tolerances are less than a millimetre and whose production rates are critical for the respect of the schedule, the construction of the sludge treatment plants when necessary, as well as all the logistics associated with the execution of the work, which is the key element of any underground project and crucial to the smooth running of the project.

Our expertise, which is sought after in all four corners of the world, has seen us pursue major projects over the years, both in the construction of metros, such as Copenhagen in Denmark and Lusail in Qatar, and in road infrastructure, such as Rijnlanroute in the Netherlands, and in hydraulic infrastructure, such as the Tideway project in the UK.

We also master conventional digging techniques (NATM or SCL), both with explosives and with mechanised methods.
Our capabilities allow us to work across the full spectrum of operations, including the design of ground improvement systems, the installation of waterproofing systems and the laying of the final coating. Tried and tested on sites as diverse as the slopes of the Atlas Mountains in Morocco for the construction of the Abdelmoumen pumped energy transfer station, and in a dense urban environment on New Zealand’s largest infrastructure project with the construction of the Auckland City Rail Link metro, our tailor-made solutions, perfectly adapted to the problems encountered, bear witness to our extensive know-how (for example, equipment specially designed for shaft sinking, or complex excavation sequences)

GEOTECHNICAL EXPERTISE ESSENTIAL TO THE SUCCESSFUL COMPLETION OF PROJECTS

Our in-house expertise in geotechnics ensures a better understanding of the suitability of the soil and the means to be used to carry out our projects. This competence is the guarantee of our operational excellence during the execution of the work.

For example, for the construction of the Doha metro (Red Line South), we proposed to replace the pedestrian accesses whose construction required the diversion of numerous urban networks by underground accesses passing under these networks, thanks to a “mega-arch” support guaranteeing low surface settlements.

We are also able to assess the impact of the excavation of our structures on the built environment and to establish the operating instructions for the tunnel boring machines accordingly. The Shieldhall Tunnel in Scotland is a perfect example: in December 2016, our teams piloted the passage of a mud pressure tunnel boring machine under the Glasgow rail link with less than 4 metres of cover, without creating any damaging settlements.

In addition, we know how to define the possible needs for ground treatment, such as freezing the soil, to allow the realisation of works under the water table. A technique used on several occasions by our teams, notably in Belgium for the construction of cross-passages of railway tunnels in the port of Antwerp, the Liefkenshoek the road tunnels of Rijnlandroute, and on the northern extension of line 14 of the Grand Paris Express.

SHARED INNOVATION AT THE SERVICE OF PROJECTS

We rely on shared innovation programmes and common operational guidelines, making the most of VINCI Construction’s transversal expertise in tunnel construction.
The development of new offers, in particular using artificial intelligence, and the emergence of new tools to further increase the security of our operational staff and our operational performance: the advantages of this integration are numerous, and allow us to remain at the forefront of technological innovations in the sector.

First low-carbon segment in France on line 18-1 of the Grand Paris Express

LinKtech, a platform for exchange and innovation uniting the entities of VINCI Construction’s Major Projects Division, and the Tunnel Factory are outstanding illustrations of our approach. The Tunnel Factory, dedicated to innovation in the use of tunnel boring machines, enables the deployment of innovative tools on our sites, in line with the defined research areas: logistics, materials and processes, data and artificial intelligence, geotechnics and geophysics, and ultra-low carbon concrete.
CAP, software developed internally by VINCI Construction, allows real-time monitoring of all the operating parameters of the tunnel boring machines. Access to this database is via the web and guarantees the reactivity and relevance of the instructions given to our current projects, in order to improve our digging performance or to accompany the sites during the most delicate passages.

Our culture of partnership with the largest industrialists in the sector also ensures the continuous development of our tools in the name of increased performance. Thus, for digging the Hallandsås tunnels in Sweden, we co-designed with our
supplier a tunnel boring machine capable of withstanding a pressure of 13 bars, a record for the time. This long-lasting partnership is the source of the deveolopment of several dual-mode machines that can be adapted to varying geology on the same project.

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