Duplex A86
The Duplex A86 is a two storey road tunnel on Paris's A86 autoroute.[1] Each storey carries two lanes of traffic, clockwise or counter-clockwise on the circular A86.
The tunnel opened in 2011, the last component to complete the A86 autoroute.[2]
The tunnels are 10.1 kilometres (6.3 mi) long.[1] The height of the roadways are 2.55 metres (8.4 ft). So they are not suitable for large trucks, only lighter vehicles. The speed limit is 70 kilometres per hour (43 mph).[3]
The tunnel boring machine, Emma, was designed so it cutting head could switch from boring through rock, to boring through water-logged soil.[2] Emma was 11.56 metres (37.9 ft) in diameter.
The tunnel is equipped with 17,500 high-pressure fire-fighting nozzles.[4]
References
[edit | edit source]- ↑ 1.0 1.1 1.2 "Duplex A86". VINCI Construction Grands Projets. 2017-03-07. Retrieved 2025-03-05.
- ↑ 2.0 2.1 "The A86 double-deck tunnel - An exceptional engineering feat". Geotechnique. 2011-01-09. Retrieved 2025-03-05.
- ↑
"Appendix 2.8 – FRANCE – the Duplex Tunnel A 86 in western Paris area" (PDF). Retrieved 2025-03-05.
The Duplex Tunnel is a single tube comprising two independent decks (or traffic levels), with unidirectional traffic on each level (two lanes in each direction). It is reserved exclusively for light vehicles with a height of 2m or less and with a laden weight of 3.5 tons or less.
- ↑
Ed Owen (2007-01-18). "Emma and the Parisians". New Civil Engineer. Retrieved 2025-03-05.
The finished tunnels have curved walls, the bottom deck needing a solid kerb to prevent cars driving up around the curved surface if they lose control. Tunnels will have the Finnish 'Hi-Fog' system installed, which can contain and put out fires extremely quickly using small quantities of water, delivered through 17,500 nozzles.