Tunnels

A86 West Tunnel,
The A86 West will form the final link of the A86 ringroad around Greater Paris.	The total project cost of the A86 West is €2.23 billion.	The tunnels are being constructed using an all terrain, made to measure tunnel boring machine.
Utilising a laser guiding system the TBM follows a precise boring course which cuts an average of 30m every day.	The installation of arch segments constructed from prefabricated reinforced concrete provide the structural finish to each tunnel.	An information system will automatically collect traffic data. This information is relayed to a safety and control office to allow quick and effective control of vehicles entering and exiting the tunnel.
The A86 West will be formed of two tunnels; one double deck for light vehicles, the other single deck for all vehicles.	The A86 West Tunnel has a number of ventilation units to ensure a permanently renewed atmosphere with efficient smoke extraction.	An emergency access shaft; there are five situated in the West tunnel and four in the East tunnel.
The East tunnel is exclusively for light vehicles with 2m-clearance height and will feature two decks each with three lanes.	The entrance to the West tunnel from the A13 motorway; the A13 interchange will now not be open until Spring 2008.

Addison Airport Toll Tunnel, Dallas, TX
In September 1997, tunnelling crews started constructing a two-lane vehicular toll tunnel under Addison Airport.	Addison Airport tunnel was excavated to a horseshoe configuration 40ft-wide by 28ft-high.	Zachry's team completed the project using specialised tunnelling equipment in varying terrain, soils and climates.
Addison Airport tunnel has six-lane toll plaza.

Airside Road Tunnel (ART) Heathrow Airport, London
During boring the new tunnel passed within 3m of the operating Heathrow Express rail tunnels.	Each end of the tunnel has 500m of ramp leading into the portals.	Steelwork was designed to support the new ART during construction.
The tunnel boring machine (TBM) was supplied by HerrenKnecht.	The 1.3km-long tunnel is constructed as twin bore and cost £140m.	The tunnel took just over a year to construct and opened in March 2007.

Devil's Slide Tunnels
The Devil's Slide Tunnels project is taking place on part of the route of the Pacific Coast Highway.	The highway in the area has experienced frequent expensive damage from landslide activity in the past, leading to the Devils Slide Tunnels being chosen as a solution to the problem.	The Devil's Slide Tunnels scheme will bypass the ecological issues previously associated with the highway.
The twin bridges at the north end of the Devil's Slide project will be complete by summer 2008.	Contractor Kiewit Pacific will use two 120t Austrian-made 'roadheader' machines for the majority of the tunnelling on the project.

Dublin Sea Port Tunnel
The Dublin Port Tunnel will provide a eight-minute link between the port and the M50 for some 20,000 vehicles per day.	The Dublin Port Tunnel is a 6.5km long dual carriageway, 4.5km of which is fully underground.	The vertical shaft at Whitehall is the largest European shaft built to date and has resulted in the excavation of over 84,000m³ of earth.
The shaft was constructed using the diaphragm walling method.	The 11.8m-diameter Herrenknecht TBM (nicknamed Gráinne) was delivered to the shaft in 103 parts.	Detail of the Herrenknecht TBM.
The Dublin Port Tunnel is open to all types of traffic, although some trucks may not fit under its 4.65m height.	Construction of the tunnel began in 2001 and boring ran from in two directions from Whitehall and back.	Transroute International is the operator of the Dublin Port Tunnel for a five-year period.

Eiksund Undersea Tunnel
Map showing route of tunnel.	Ørsta bolt – 37,000 bolts were used in the tunnel’s construction.	Tunnelling operations underway. Note the conduit services line in the ceiling.
Engineer on a gantry carrying out a survey of the tunnel ceiling.	Truck and digger removing spoil from tunnel entrance.	Slurry cement process underway.
CT bolts being placed to support tunnel walls and ceiling.

Göta Tunnel, Gothenburg
Map showing the area of Götaleden with the route of the new road tunnel.	Cross section schematic showing the two tunnels.	The Göta Tunnel on its day of opening.
Graphical representation of the redeveloped Södra Älvstranden area.	Gothenburg Opera House, which will be linked to the city centre once the Södra Älvstranden area has been developed.	The area of Södra Älvstranden in February 2007, with nearby businesses already undergoing face lifts in preparation for the new open Södra Älvstranden.
Södra Älvstranden in February 2007.

Grouft Tunnel
The Grouft Tunnel will be sealed with a membrane and finished with shotcrete.	The flexible sealing membrane.	Work on the rescue tunnel.
The downhill tunnel will have two lanes and the uphill tunnel three lanes.	The north portal of the Grouft Tunnel.

Herren Tunnel, Lübeck
The Herren Tunnel is a road tunnel in Lübeck opened in August 2005.	The Herren Tunnel replaces the ageing bridge over the Trave River.	The tunnel was sealed by lining it with 3,640 prefabricated concrete segments, put in place immediately behind the TBM.
The Herren Tunnel is a twin parallel tube tunnel.	The twin tunnels were mainly cut using a TBM.	The cutting edge of the TBM.
The TBM being assembled in the access shaft.	Excavation for one of the ramps to lead to the tunnel entrance.	Components of the TBM being transported for assembly.
The interior of the tunnel before the road surface was laid.	The entrance of the finished Herren Tunnel.	Herren Tunnel toll booths.

Lane Cove Tunnel, Sydney
The Lane Cove Tunnel is a key link in Sydney's orbital motorway network.	Artist's impression of the entrance / exit road from the Lane Cove Tunnel.	Looking east at the junction of Epping Road and Mowbray Road West in Lane Cove, with the western portals of the tunnels on the right.
Alpine Miner ATM 105-IC roadheaders from Voest.	Looking west along Longueville Road at the new Parklands Avenue bus interchange, connected to the Lane Cove shopping centre by a new pedestrian bridge.	Looking west along the rebuilt Gore Hill Freeway under the rebuilt Reserve Road bridge.
One of the pedestrian and cycle ramps installed as part of the project.	The eastern end of the tunnel, which begins as two lanes and then turns into three.	The Gore Hill Freeway has an additional new lane in each direction to act as transit lanes.

Medway-Canvey Island Thames Crossing
The new Medway-Canvey Island crossing is still at the design stage, but a proposal has been made to the DfT and the EA.	Canvey Island will be central to the whole scheme which could include a tidal power station and a further tidal barrier.	The Thames Estuary has always been a natural barrier between Kent and Essex.
The Department for Transport and the Environment Agency are investigating proposals for a project to link Medway and Canvey Island.	The rail tunnel part of the proposed Medway-Canvey Island project will carry a line to link with the Crossrail project in London.	The Medway-Canvey Island tunnel will be laid in a trench dredged across the bed of the Thames Estuary.

Nam Wan Tunnel
Blast doors to muffle the sounds of blasting during the Nam Wan Tunnel construction.	Inside the westbound tunnel.	Tunnel ventilation jet fan.
Smoke extraction vents being installed.	Installation of vitreous enamel panel supporting frame.	A computer-generated image of the Nam Wan Tunnel portal.
Construction of the Nam Wan Tunnel and motorway.	Nam Wan Tunnel portal retaining wall.

New Tyne Crossing
The new Tyne tunnel will be constructed alongside the old tunnel to ease congestion.	The New Tyne Crossing project will cost £260m and will refurbish the old tunnel as well as constructing a new one.	Currently, on the existing Tyne Tunnel, there are severe traffic issues as the road narrows from a dual carriageway to a single carriageway.
Traffic congestion through the tunnel has a negative effect on the A19, particularly during busy periods.	The new Tyne Tunnel will be completed and the old tunnel refurbished by 2011.

Route 29 Tunnel, Trenton, NJ
Looking north, completion of the remedial excavation and backfill at the foot of Lalor Street (December 2000).	Looking northwest, placement of the AASHTO precast girders for the Ramp D bridge which will connect with Lalor Street.	Looking east to homes on adjacent Lamberton Road, a front end loader clears dirt from a section of the project (March 2000).
Workers prepare the river bank for the new road in June 1999.

Saaser Tunnel
Robit forepoling of steel piles drilled into the soft ground.	Bolting with Tamrock jumbo.	Part of the escape system of the tunnel.
Tunnel boring machine.	Map showing the location of Saas.

San Cristóbal Tunnel
The San Cristóbal tunnels were excavated using drill and blast methods.	The San Cristóbal tunnels are only in limited use at the current time.	The tunnel has escape exits and refuges at regular intervals along its length.
The northern portal of the San Cristóbal tunnels.	The San Cristóbal tunnel is part of a larger 4km-long project linking the business areas of Santiago to the northern suburbs.

SMART (Stormwater Management And Road Tunnel), Kuala Lumpur
Installation of toll booths.	Map showing the location and route of the stormwater tunnel.	Graphical representation of a cross-section of the tunnel.
Storm Control Centre.	Road showing tunnel toll booths.	One of the 2 x 13.2m diameter tunnel boring machine – one of the world’s largest.
One of the tunnel boring machines.	Schematic showing how the tunnel will work in differing climatic conditions.

Thu Thiem Tunnel
The new District 2 is set to become a prosperous commercial centre.	Construction was delayed because of difficulties encountered during site clearance.	Lack of road development in Ho Chi Minh City has lead to heavy traffic.
The tunnel project is part of the larger East-West highway project.	The centre of Ho Chi Minh City during rush hour.

Tunnel du Mont Sion
The TBM has already completed the first drive.	The precast yard will produce all the tunnel linings.	There is also the service infrastructure for disposing of tunnel spoil and maintenance.
The TBM was christened Adelaide in October 2006.	The cutting surface.	The second tunnel drive to the east is due to started in mid-2007.

Uetliberg Tunnel, Zurich
The Uetliberg Tunnel, part of the new N4/N20 Zurich western bypass in Switzerland, is the largest tunnel and stretch of roadway of the bypass at 4.4km.	Basel tube.	Aerial view of the assembly area Landikon including construction areas Reppischtal and Schacht Eichholz.
Profile of Uetliberg Tunnel.	Boring at section Diebis.	Assembly of tunnel boring machine (diameter 5m).
Location map of Swiss highways around the Uetliberg Tunnel. (All images copyright: Amberg Engineering Ltd.)

Westerschelde Tunnel
The two twin-tunnels of the Westerschelde Tunnel run 12m apart and have two 3.5m wide lanes for traffic each. All images courtesy of NV Westerschelde Tunnel.	With an estimated cost of €726 million, the Westerschelde Tunnel will provide a faster and more economical route for around 27,000 vehicles a day between Ellewoutsdijk in Zuid-Beveland and the Zeeuws Vlaanderen region near Terneuzen.	The Westerschelde tunnel boring machines (TBM) worked for 24 hours a day, six days a week to meet construction targets.
Inside the 8m cylinder hydro shield under the Westerschelde.	One of the 53,000 concrete lining segments being put in place.	The particular challenge that faces the construction of this tunnel is the soft clay that has to be bored through.
The fire protection sheathing of the tunnel is designed for a fire-load of 1,350ºC.	The two tunnels are the deepest ever to be driven worldwide and are the greatest challenge to date in terms of machine layout, processing and construction.

Yangtze River Tunnels
The Yangtze River tunnels are being constructed using two TBMs.	The under-river tunnels will link the mainland with the island of Changxing.	The two tunnels will require the disposal of 2.7 million cubic metres of earth by the time they are completed.
The twin tunnels across the Yangtze river will be completed by 2010.	Tunnelling with the first TBM began in September 2006, with work on the second tunnel beginning in December that year.	The two TBMs being used for the Yangtze River project are the largest in the world with a diameter of 15.43m.

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