Engineering:Tunnel hole-through
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Dismantling the tunnel boring machine 10 days after the hole-through on the Gotthard Base Tunnel in Switzerland .
Tunnel hole-through, also called breakthrough, is the time, during the construction of a tunnel built from both ends, when the ends meet,[1] and the accuracy of the survey work becomes evident. Many tunnels report breakthroughs with an error of only a few inches, for example:
- the 1858 Blue Ridge Tunnel – 6 inches (150 mm)
- the 1944 Blue Ridge Tunnel replacement – 4 feet (1.2 m) - 1944
- the Lötschberg Base Tunnel – 10 cm[2]
- the Holland Tunnel - 1 cm[3]
See also
- Cascade Tunnel
References
- ↑ "Governor Rockefeller and Mayor Lindsay Attend 'Holing Through' of 63d St. Tunnel". The New York Times. October 11, 1972. https://select.nytimes.com/gst/abstract.html?res=FA0A12FF3E591A7493C3A8178BD95F468785F9. Retrieved January 24, 2017.
- ↑ Lotschberg
- ↑ "ASCE Metropolitan Section - Holland Tunnel". https://www.ascemetsection.org/committees/history-and-heritage/landmarks/holland-tunnel.
External links
![]() | Original source: https://en.wikipedia.org/wiki/Tunnel hole-through.
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