• WTC 2017: Surface challenges – Underground solutions

WTC 2017: Surface challenges – Underground solutions

Published on 10.07.2017

BG attended the World Tunnel Congress (WTC) in Bergen at the beginning of June and made two presentations.

Organised by the International Tunnelling and Underground Space Association (ITA) in cooperation with the Norwegian Tunnelling Association, the WTC brings together European and international experts in underground construction, including researchers, design engineers, suppliers, manufacturers and companies. This year the theme was “Surface challenges – Underground solutions”.

Two BG specialists, Stéphane Lévy and Xavier Guigas, made a presentation on the Saverne tunnel, another major project that the Group is involved with. Based on the publication “Aerodynamic Sizing of High-Speed Train Tunnels – The Saverne Tunnel Case” that was produced jointly with other BG project managers, this presentation described the aerodynamic studies and tests carried out in the Saverne tunnel (a 4-kilometre twin-tube tunnel) which is part of the new East-Europe high-speed rail line. The authors showed in particular how pressure variations in tunnels and trains impact the objective of ensuring an acceptable level of comfort and adequate hearing protection for passengers.

BG project manager Etienne Garin presented the lessons learned from the design and implementation of the large caverns at Nant-de-Drance, based on an article which several BG experts wrote jointly with Gérard Seingre, general site manager at Nant-de-Drance.

In this article entitled “Lessons learned from design and construction of the Nant-de-Drance Power Powerhouse”, the authors speak of the ambitious work undertaken to build the new power station, most of which was carried out underground (17 kilometres of tunnels, two vertical shafts of 444 metres and six caverns). Located at a depth of 600 metres, the main cavern required specific excavation, underpinning and cladding operations. Calculations were optimised using rock analysis, 3D modelling of the finite elements and sampling of the unstable bedrock. The construction design was also a major challenge owing to the unusual loads supported by the structure during the building and operational phases, and to the large amounts of concrete used.

Aside from being invited to speak at the event, Etienne Garin was also selected to represent Switzerland in ITA’s Working Group 19 which focuses on conventional tunnelling.


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