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Slightly different office to most

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(@alexandert)
Posts: 29
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Topic starter
 

Seems most surveyors on here work mainly in the lovely great outdoors so figured I'd share my typical office

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IMG 1897
IMG 1669

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IMG 1387
 
Posted : January 18, 2022 12:18 pm
FL/GA PLS
(@flga-pls)
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Those pics are great! Please keep us informed. ?????ÿ

 
Posted : January 18, 2022 12:25 pm
Williwaw
(@williwaw)
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What are we looking at??ÿ

Just because I'm paranoid, doesn't mean they aren't out to get me.

 
Posted : January 18, 2022 12:55 pm
hi-staker
(@hi-staker)
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What tunnel boring are you working on? How long does your typical job last?

 
Posted : January 18, 2022 1:07 pm
(@alexandert)
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Topic starter
 
Posted by: @williwaw

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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Posted by: @hi-staker
?ÿ
What 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

 
Posted : January 18, 2022 1:07 pm

MightyMoe
(@mightymoe)
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Very cool!!!

?ÿ

 
Posted : January 18, 2022 1:15 pm
Williwaw
(@williwaw)
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@alexandert That's pretty dang cool! Surmised it was something like that or a particle accelerator.

Just because I'm paranoid, doesn't mean they aren't out to get me.

 
Posted : January 18, 2022 1:19 pm
(@alexandert)
Posts: 29
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Topic starter
 

@williwaw?ÿ

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!

 
Posted : January 18, 2022 1:36 pm
bill93
(@bill93)
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@alexandert?ÿ

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.)

 
Posted : January 18, 2022 1:51 pm
kevin-hines
(@kevin-hines)
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@alexandert

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!!!

 
Posted : January 18, 2022 1:56 pm

holy-cow
(@holy-cow)
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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?

 
Posted : January 18, 2022 2:55 pm
brad-ott
(@brad-ott)
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Very cool.

 
Posted : January 18, 2022 3:18 pm
(@alexandert)
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Topic starter
 
Posted by: @bill93

@alexandert?ÿ

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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@kevin-hines

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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Posted by: @holy-cow

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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?ÿ

 
Posted : January 18, 2022 3:31 pm
jimcox
(@jimcox)
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@alexandert

way cool

 
Posted : January 18, 2022 9:57 pm
party-chef
(@party-chef)
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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.

?ÿ

 
Posted : January 19, 2022 3:23 am

(@alexandert)
Posts: 29
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Topic starter
 
Posted by: @party-chef

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.?ÿ

?ÿ

We're using CAP as its a subsidiary, most people at work say VMT is really good (I've not used it).

If you look at (picture 2) you can see some retros which we used. CAPs own surveyors went to HK factory in Germany and surveys a bunch of retros they placed on the H-frame to coordinate them to the machine.

Once the TBM was reassembled on site, we welded reference prisms on then surveyed those with the retros. CAP then used the retros to coordinated the offset values for the prisms relative to the TBM from their survey at HK.

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.

I try not to take pictures of all that!?ÿ ???œ?ÿ

 
Posted : January 19, 2022 12:57 pm
jaccen
(@jaccen)
Posts: 450
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Very cool.?ÿ Please keep us updated as "niche" surveys like this are always fun to read about.

 
Posted : February 15, 2022 10:46 am
squirl
(@squirl)
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Excellent! Thank you for sharing!

T. Nelson - SAM

 
Posted : February 15, 2022 12:13 pm
beuckie
(@beuckie)
Posts: 347
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No gyro used? How long was your start reference line? I did some tunneling before and was always anxious to know if they would show up where they needed to be.

Not these kind of tunnels but 2m diameter in curbs for a few hundred meters. Exciting but stressful jobs

 
Posted : February 15, 2022 1:06 pm
john-hamilton
(@john-hamilton)
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I did some gyro azimuths for a pair of hydro tunnels in Peru, they had me come in when they were getting close to breakthrough, drilling from both ends. I think one was 22 km and the other a bit less. Had a bit of a water problem...

image
image

We had to ride in the mine cars to get to the face, about 45 minutes each way

image

Here was their "low-tech" TBM guide target, as long as the laser was inside the hole, they were online

image

I had to observe a surface line to calibrate, on triangulation pillars

image

The TBM was nowhere as clean looking. They actually got one of them stuck, and had to bring in another one to clear a path to get it out.?ÿ

They sent me pics when they broke through, not sure what I did with those.?ÿ

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Posted : February 15, 2022 1:38 pm

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