Eyholz tunnel

Eyholz tunnel
Construction site on the west portal of the tunnel in May 2010. The portal can be seen to the left of the hall. In the middle of the picture the Staldbach Bridge , on the right the portals of the Visp Tunnel .
use	Road traffic
traffic connection	A9 motorway
place	Visp , Brig-Glis
length	North tube: 4,255 m South tube: 4,231 m
Number of tubes	2
cross-section	Single tubes: 110 to 130 m² per tube. Branch caverns: 318 m²
Largest coverage	820 m
construction
Client	Office for National Road Construction , Canton Valais
building-costs	560 million euros (as of 2013)
start of building	2007
completion	April 13, 2018
Situation map
location
Coordinates
West portal	634305  /  125230
East portal	637598  /  127385

 Map with all coordinates: OSM | WikiMap

The Eyholztunnel is a 4.25 kilometer long motorway tunnel on the Swiss A9 motorway , more precisely the southern bypass of Visp in the canton of Valais . Construction of the tunnel began in 2005 and the traffic handover took place on April 13, 2018.

construction

The construction of the tunnel was entrusted to the Main Tunnel Eyholz working group (Arge AHE), to which the companies Frutiger AG , Interalp Bau AG from Visp, CSC - a subsidiary of the Italian Salini Impregilo - and the Austrian Jäger Bau belong. The tunnel leads through loose rock, breccia and limestone mica schist . In the loose rock, a 315 m stretch had to be made with a jet umbrella that was brought in using the jet grouting method . The rest of the tunnels were excavated using blasting .

The excavation was transported to the north on a conveyor belt via a tunnel created in the axis of the northern tube of the Visp tunnel , which was excavated with a tunnel boring machine and had a diameter of 4.2 m. It was completed in 2006 and was later extended to the north tube of the Visp tunnel. From the north portal of the tunnel, the excavation reaches the Goler deposit near Raron via another 3.2 km long conveyor belt . No truck transports were therefore necessary to transport the excavated material.

Preparatory work for the tunnel construction began in 2005. First, the drives were carried out through the loose rock at the east portal and the branch caverns were excavated in 2008, which had an excavation width of 26 m. The excavation was particularly difficult over a length of about 85 m of the southern cavern because the area was cut by a graphite zone that was not very stable .

The main driving of the south tube began in April 2009, that of the north tube on May 23, 2009. The breakthroughs took place on August 31, 2012 in the south tube and in October 2012 in the north tube. The traffic handover took place on April 13, 2018.

In connection with the construction, there were discussions about the additional demand of 60 million Swiss francs made by AHE . It was founded with increased effort because of the difficult geology, changed concrete and disrupted construction process. The consortium used inferior quality concrete over a length of 600 m for the false ceiling to the ventilation duct, which had to be demolished and replaced.

Building

The tunnel is used for through traffic in the Rhone Valley , but also for traffic from Zermatt and Saas-Fee in the direction of Brig and Simplon Pass , which no longer has to be led through Visp.

The west portal is located at the Staldbachbrücke , shortly after the portal each tube widens to a branch cavern in which the half-connection Vispertal Ost is located. The exit for traffic from Brig in the direction of Vispertal is in the north tube , which necessitated a 280 m long cavern. The driveway for traffic from the Vispertal in the direction of Brig is located in the south tube, which required a 445 m long cavern. The entrance and exit are connected to single-lane tunnels that connect to the road in the Vispertal. The other portal of the A9 tunnel is located east of Eyholz near the hamlet of Grosshüs in the municipality of Brig-Glis .

In the two tubes with a horseshoe-shaped cross-section, two lanes of the A9 run each with a side path one meter wide on both sides. Under the carriageways of each tube there is a 2 m wide and 2.9 m high accessible utility duct, above the carriageway there is a ventilation duct with a cross section of 13 m², which is separated from the carriageway tunnel by a false ceiling. The tunnel tubes run at a distance of 30 m from one another, which is reduced to 10 m at the portals. They are connected to one another with 16 cross passages. There is a ventilation center at each portal, which can extract the smoky air via the ventilation duct in the event of a fire outbreak. In normal operation, ventilation is provided by ceiling fans.

literature

• Georg Anagnostou, Heinz Ehrbar (Eds.): Tunneling Switzerland . vdf Hochschulverlag AG, 2016, ISBN 978-3-7281-3547-6 , Tunnel Eyholz, p. 244–249 ( limited preview in Google Book Search [accessed October 9, 2016]).

Web links

• A9 connects the Valais. Canton of Valais, accessed on October 9, 2016 (official website of the A9 construction site). 

Individual evidence

1. ↑ Eyholz tunnel: break through the north tube. In: tunnel-online.info. April 2013, accessed October 9, 2016 . 
2. ↑ Alex Schneider: Underground branching caverns in the Eyholz tunnel on the A9 national road, Visp bypass (VS) . December 13, 2007 ( ethz.ch [PDF; 4.4 MB ]). Underground branch caverns in the Eyholz tunnel on the A9 national road, Visp bypass (VS) ( Memento of the original from October 9, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.  
3. ↑ ARGE demands 60 million francs. In: Walliser Bote online (1815.ch) . Retrieved October 9, 2016 . 
4. ↑ Cyrill Pinto: New million dollar scandal in Upper Valais: Valais officials are giving away our tax millions here. In: Blick.ch . May 22, 2016. Retrieved October 9, 2016 .