Seems most surveyors on here work mainly in the lovely great outdoors so figured I'd share my typical office
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Those pics are great! Please keep us informed. ?????ÿ
What are we looking at??ÿ
What tunnel boring are you working on? How long does your typical job last?
What are we looking at??ÿ
Sorry my bad I should have said.
They're taken from a TBM (Tunnel Boring Machine) It pushes forward (picture 2) and essentially cuts into the earth and lays rings behind it creating the tunnel.
The total station is used to provide position for guidance system which the pilot operating the machine uses to follow the tunnel alignment.
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?ÿWhat tunnel boring are you working on? How long does your typical job last?
It's for a high-speed rail in the UK. ?ÿ There's a few tunnels to construct on this section in total 5 years probably (anyones guess is probably as good) but most of the time is preparation and temporary works rather than the actual tunnelling.
This tunnel in the picture should done in 5 months of actual tunnelling, but then we have to do one adjacent and do the cross passages and works after.?ÿ
Very cool!!!
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@alexandert That's pretty dang cool! Surmised it was something like that or a particle accelerator.
I'd love work on a particle accelerator, been keeping my eye out for jobs for the new supercollider at CERN, heard the level of accuracy they have to work to is crazy!
I believe I saw a report for an accelerator project that quoted measurements as x,xxx.xx millimeter. (Or if it was in Europe, x.xxx,xx mm.)
I watched an episode of Modern Marvels a few years back where they were adding tunnels to the subway in either London or Liverpool.?ÿ The path of the new tunnel took the crew between two existing tunnels where clearance was critical.?ÿ In addition to the underground mapping accuracy of the project which was phenomenal, they also had to provide continuous remote monitoring on historical buildings in the downtown area.?ÿ An extremely interesting niche in the world of Land Surveying!!!
Assuming the wall of the tunnel where the mount is attached in the first photo must be concrete.?ÿ How stable is that location based on differing pressures on the other side of the tunnel wall?
Very cool.
I believe I saw a report for an accelerator project that quoted measurements as x,xxx.xx millimeter. (Or if it was in Europe, x.xxx,xx mm.)
Yeah I believe the article I read was referencing sub-millimetres think one was using micrometre as units of measurement when positioning the actual accelerator (don't quote me on that though)
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Yeah London has quite a challenge threading new tunnels amongst ?ÿall of the existing tunnels and building piles, even getting the machinery down to start the tunnelling.
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Assuming the wall of the tunnel where the mount is attached in the first photo must be concrete.?ÿ How stable is that location based on differing pressures on the other side of the tunnel wall?
These brackets/mounts are pretty solid. Most pressure will be from the TBM its self as it advances forward. The void behind rings get grouted and this allows the pressure from the TBM to be transferred to the surrounding earth.
Those brackets (picture 1) are temporary and get moved forward with the TBM as it advances anyway. We place more permanent ones further behind and use these to traverse from outside regularly up to the temporary ones to check/update their coordinates.
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Looking good, I have spent some time working on tunnels also.?ÿ
I am interested in learning more about how other people set fiducials.
I have heard that when you order a Heerenknecht machine equipped with VMT that the spigots come installed and that you just need to survey the machine and fiducials and drop the NEZ into VMT.?ÿ
I have used TACS, ZED, and Enzan but never VMT.
Thanks for sharing, it looks like the operations are clean and safe! Good for you guys for keeping an operation that you can take pictures of without it looking like a disaster.
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