Tunnel
| Fort Pitt Bridge | ||
The Fort Pitt bridge in Pennsylvania. |
Fort Pitt bridge elevation drawing. |
Sideways view of the Fort Pitt bridge. |
Exterior view of the Fort Pitt tunnel. |
A side view of the Fort Pitt bridge. |
View of downtown Pittsburgh and the Point from Mt. Washington across the Monongahela River. Fort Pitt Bridge is in the right foreground. |
| The Big Dig | ||
Spools of wire ropes run along the length of the underside of the jacked tunnel sections, providing lubrication as the concrete boxes move ahead. |
Equipment inside the tunnel box during jacking. |
Tunnel jacking pit near South Station, looking east. Here westbound lanes of I-90 will be pushed or jacked beneath railroad tracks (train passing at top). |
Tunnel box for I-90 eastbound under construction in a jacking pit near South Station. |
Grinding mechanism of an excavator called a "road header" that chews through frozen soil at the face of jacked tunnel sections under railroad tracks near South Station. |
Temporary beams supporting the elevated Central Artery at Causeway Street in downtown Boston. |
Road header machine grinding away soil beneath South Station railroad tracks. |
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| Westerschelde Tunnel | ||
In November 1997 building started on a 6.6km tunnel underneath the Westerschelde in Zeeland, the Netherlands. |
The soil in the area is made from soft Boom clay stratum and therefore the construction of tunnels is very difficult. |
The two twin-tunnels run 12m apart, they have 11.3m mixshields in the outside diameter, and each will have two 3.5m wide lanes for traffic. |
With an estimated cost (excluding tax) of €726 million (Guilders 1.6 billion), the Westerschelde Tunnel is important in that it is the first engineering structure designed in a fundamentally correct way on the basis of an expected service life of 100 years. |
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. |
Schöma have provided underground wagons and locomotives for transporting people and equipment to the site. |
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