Questions tagged [tunnels]
18 questions
21
votes
1 answer
Why does the Channel Tunnel enter the ground around 10 km from the coast?
I know that digging tunnels is always much more costly than building ways or train above ground.
Why doesn't the Channel Tunnel start around the coastline? Why does it have an around 10 km long portion under land on the British side?
peterh
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7
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3 answers
How are tunnels dug from two endpoints joined?
Let's assume I want to build a subway system. I dig two subway stations and now I start digging a tunnel from both of these endpoints simultaneously.
How can I ensure that the two tunnels dug from the different endpoints meet in the middle? I don't…
juhist
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5
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1 answer
Is a Transatlantic tunnel technically possible today? How feasible would it be?
The question has been surfacing periodically in the media and books over the past 100 years or so. I realize we're talking about a lot of material and work hours to begin with; the subsequent maintenance would be a nightmare. There are no power…
Ricky
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3
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1 answer
Why culmination points in tunnels?
The shortest connection between two portals would be a tunnel with constant gradient. Why do long tunnels instead rise from both portals to a culmination point, introducing unnecessary steep gradients?
Some thoughts: If it is for drainage, this…
Andreas
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3
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1 answer
Tunnel at depth problem
I was browsing for Gibraltar strait tunnel where due to greater depth it is not being build.
Question popped up as to why tunnel building is difficult at lets say 1000m. we have coal mines which go deeper than that, than why not tunnel?
murmansk
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3
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1 answer
How wasn't Thames Tunnel flooded during construction?
I have read the Brunel's shield directly exposed ground which was then excavated by the workers. But the construction was done just a few meters under the seabed. How wasn't the tunnel flooded immediately?
I think of small pits that children dig on…
olegst
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2
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1 answer
Why are tunnel boring machines not using cone-shaped drills?
The surface area of the head of a tunnel boring machine is usually flat. A cone-shaped head would increase the surface area. The question is if it could speed up the boring process.
I know that with current machines the boring process is also…
clash
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1
vote
2 answers
Light frame at tunnels and bridges
I actually don't know on which SE to ask this.
Since there are quite often too low bridges/tunnels, or too high trucks or trailers, why isn't there 100m ahead of those bridges, some light frames (like football goal cage) the size and height of the…
user721108
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1
vote
1 answer
Is tunnel boring considered groundworks?
The wikipedia page for groundworks (earthworks) does mention contour trenching and cut & fill but not a word about bring tunnels. Is a bored tunnel part of groundworks discipline/field? If not what discipline does it belong to.
1
vote
1 answer
What casued periodic waviness in the sidewalls of this tunnel?
It looks like the digging of this ISIL tunnel introduced periodic waviness in the sidewalls of the tunnel. Similar (related?) waviness can sometimes be observed on dirt roads. What is the origin of that periodic waviness?
(source)
Sparkler
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0
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1 answer
What are design considerations for an RCS test range be relocated fully underground?
Sites like the Lockheed Helendale RCS or the Tonopah test range are only known to have an underground pit to support raising or lowering of test articles. But is it technically possible to have a fully underground test range?
For example the…
Nederealm
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0
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1 answer
Tunnel lining vs structural support
Is tunnel lining the same thing as tunnel structural support? And then also there is always the initial and final lining? Are three all different things? And how do they relate to waterproofing? It seems that there are endless methods which are a…
upstream
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0
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2 answers
Have tunnel boring machines been mass produced? What are the difficulties in mass producing a tunnel boring machine?
Tunnel boring machines are a common tool in deep tunnel construction. I am curious if they have ever been mass produced in specific types. What are the possible problems in (a possible) mass production of such machines?
Erkin Alp Güney
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0
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1 answer
Is a granite block tunnel longer lasting than reinforced concrete?
Assumptions
Building Process exists
Waterproofing is able to be replaced
Notes
Please answer yes or no with the science backing.
This question is only about the strength and lifespan.
This question is NOT about cost, or process.
Additional…
Dev Slocum
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0
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1 answer
Does tunnel lining made of cast iron tubings actually accept all the mechanical loads?
Here goes a recently opened underground railway station in Moscow, Russian Federation (image is from here)
On the left is an undecorated (just painted and it will likely remain this way) tunnel wall. The tunnel wall is lined with cast iron tubings…
sharptooth
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