El Teniente, Chile
Since starting operation in 1905, the El Teniente mine south of Santiago, Chile, has only continued its expansion.
Located in the Andes mountain range, the world’s largest copper mine continues its growth by digging ever deeper to extend its productive life.
Overall, the mine has nearly 2,000 miles of underground tunnels and almost 1,000 miles of underground roads.
Metropolitan Area Outer Underground Discharge Channel, Japan
It may not have a catchy name, but the world’s largest underground flood diversion facility is stunning nonetheless.
At 72 feet below the ground about 20 miles from Tokyo, the facility has 59 pillars—each weighing 500 tons—that support the ceiling over this 580-foot-long, 255-foot-wide and 82-foot-long structure that remains open to the public for tours, save, of course, for the few times a year it gets used.
Gotthard Road Tunnel
The Gotthard Road Tunnel in Switzerland runs from Göschenen in the canton of Uri at its northern portal, to Airolo in Ticino to the south, and is 16.9 kilometres (10.5 mi) in length below the St Gotthard Pass, a major pass of the Alps.
At the time of the construction, in 1980, it was the longest road tunnel in the world; it is currently the ninth-longest. The Gotthard Road Tunnel is one of the three tunnels that connect the Swiss Plateau to southern Switzerland and run under the Gotthard Massif, the two other being railway tunnels, the Gotthard Tunnel (1882) and the Gotthard Base Tunnel (2016).
All three tunnels bypass the Gotthard Pass, an important trade route since the 13th century.
Tunnel of Large Hadron Collider
The Large Hadron Collider (LHC) is the world’s largest and most powerful particle collider, most complex experimental facility ever built, and the largest single machine in the world.
It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and engineers from over 100 countries, as well as hundreds of universities and laboratories.
It lies in a tunnel 27 kilometres (17 mi) in circumference, as deep as 175 metres (574 ft) beneath the France–Switzerland border near Geneva, Switzerland.
It is an important local railway station in the city of Zürich, on the Zürich-Rapperswil, Zürich-Winterthur, Zürich-Uster lines of the SBB CFF FFS (Swiss Federal Railways).
The rail approaches at both ends are in tunnel, with the Hirschengraben Tunnel to Zürich Hauptbahnhof to the north. To the south the line divides inside the tunnel, with one route traversing the Zürichberg Tunnel to Stettbach station and the other a single track tunnel to Tiefenbrunnen station.
The station can be accessed from either side. An underground retail arcade runs the length of the station below the tracks and provides access between the platforms and station entrances.
Underground access is supplemented by two bridges which span the station, one carrying a footpath and the other restricted road traffic.
The Boston Central Artery/Tunnel project
This was also known as the “Big Dig” is one of the largest and most complex urban transportation project ever undertaken in the United States. As the result of more than 30 years of planning and 12 years of construction, the project was developed to alleviate the major traffic congestion that had plagued Boston for years.
Before the project started, the elevated six-lane highway, called the Central Artery, carried close to 200,000 vehicles a day through the center of downtown Boston.
The roadway was considered one of the most congested highways in the United States with 10 hours of traffic each day. The accident rate on the deteriorating elevated highway was also four times the national average for urban Interstates. The same problem plagued the two tunnels under Boston Harbor between downtown Boston and East Boston/Logan Airport.
- The project placed 3.8 million cubic yards of concrete, enough to build a sidewalk three feet wide and four inches thick from Boston to San Francisco and back three times.
- Reinforcing steel used in the project would make a one-inch steel bar long enough to wrap around the earth at the equator
- The Ted Williams Tunnel interface is 90 feet below the surface of Boston Harbor, the deepest such connection in North America.
- The project’s underground utility relocation program moved 29 miles of gas, electric, telephone, sewer, water, and other utility lines maintained by 31 separate companies.
- 5,000 miles of fiber optic cable and 200,000 miles of copper telephone cable were installed.
- The 10-lane cable-stayed hybrid bridge is the widest ever built and the first with an asymmetrical design, using both steel (in the main span) and concrete (in the back spans).
The project was completed in 2006 and since completion the total vehicle-hours of travel on project highways dropped 62 percent between 1995 and 2003―saving travelers about $168 million annually in shorter travel times and lower transportation costs.
The project also created more than 300 acres of new parks and open space, including 27 acres where the existing elevated highway stood, 105 acres at Spectacle Island, 40 acres along the Charles River, and 7 acres as part of an expanded Memorial Stadium Park in East Boston.
Sanford Lab, South Dakota
Once the Homestake Gold Mine in Lead, South Dakota, the continent’s largest and deepest former gold mine has given way to the Sanford Lab, almost 5,000 feet below ground.
And there’s room for expansion, as the mine dips 8,000 feet below the surface. Stretching to the equivalent of more than six Empire State buildings, the lab at 4,850 feet deep allows the study of dark matter, shielded from interfering cosmic rays by the mass of earth above it.
Wieliczka Salt Mine, Poland
Starting in the 13th century and continuing through to 2007, the Wieliczka Salt Mine outside of Krakow, Poland, saw crews pull salt from the 1,000-foot-deep mine that stretches around 180 miles in length.
With such an influential history, the mine was put to use instead of merely closed and is now full of galleries and chambers on the nine floors—with three open to the public
Dürig AG, Through Station Löwenstrasse, Zurich,
Zurich architects Dürig designed angular concrete frames to indicate the position of staircases and escalators at the Swiss city’s main railway station, which descend from the platforms to a new subterranean station and shopping precinct.
The station comprises two 420-metre-long platforms that will be able to accommodate longer intercity services arriving into the four adjacent tracks when all the building work is completed.
Sandwiched between this level and the existing overground station is a new shopping centre that extends east and west on either side of the River Sihl, which flows from north to south beneath the main station.
“Vertical means of access such as stairs, escalators and lifts are formed as continuous solid-structure conveyance cores running through all the levels,” the architects said.
“Their geometry responds to the existing built surroundings, forming individual volumes that, in part, also perform structural functions, for instance acting as bearings for existing supports in the listed roof of the railway station,” the architects added.
In addition to the sloping entrances to staircases and escalators, simple concrete boxes contain lifts that descend through slanted shafts intersecting the shopping level.
The unusual angled shafts are required because the tracks for the new underground station and the terminal above could not be aligned.
Throughout the underground spaces, large passages facilitate straightforward circulation even when the station is busy. The open layout of these areas also allows passengers a clear sight of overhead signage.
Image links: Google