Questions tagged [tunnels]

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Building a land bridge across the Bering Strait

Would building a land bridge across the Bering Strait be more cost effective then building an actual bridge or tunnel? Much like how the Chinese build artificial islands in the South China Sea.
user41388's user avatar
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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 ...
Nederealm's user avatar
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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 ...
upstream's user avatar
  • 457
3 votes
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?...
Andreas's user avatar
  • 131
0 votes
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 ...
Erkin Alp Güney's user avatar
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Is a granite block tunnel longer lasting than reinforced concrete? [closed]

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 ...
Dev Slocum's user avatar
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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. ...
sharptooth's user avatar
  • 2,099
0 votes
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Why do normal tunnel boring operations not use the dirt (from the boring itself) for reinforcement rather than bringing it from other sources?

According to Elon in this video (@13:06), he states that the reinforced segments are 70% just dirt, but in normal tunneling, they actually truck the dirt out and bring new dirt in which seems very ...
meteor inc's user avatar
1 vote
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 ...
clash's user avatar
  • 113
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 (...
user avatar
3 votes
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 ...
murmansk's user avatar
  • 155
7 votes
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 ...
juhist's user avatar
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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 ...
ApoptegamyCivilEngineer's user avatar
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What lining design holds better for a tunnel? Spiral lining or cylindrical lining?

Hy everyone :) I don't know much about structural engineering, maybe spiral lining and cylindrical lining are not the proper ...
AIon's user avatar
  • 157
3 votes
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 ...
olegst's user avatar
  • 131
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 ...
Sparkler's user avatar
  • 223
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 ...
peterh's user avatar
  • 2,359
6 votes
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 ...
Ricky's user avatar
  • 309
-2 votes
2 answers

Is it possible to use lasers to build tunnels instead of mechanical digging machines? [closed]

I know lasers can cut or create holes on some hard materials such as diamond and metals. Is there any similar concept in tunnel engineering? If not, what are the difficulties?
Gstestso's user avatar