[Burnaby] Gilmore Place | 214.8m | 64fl | Phase 1 Completed

[Zepfancouver]

Originally Posted by Klazu

...have they been continuously reinforced, as they went on with the excavation?...

Good question, I would have like to have seen more details on that process, the thread does have more photos but to few.

Originally Posted by jollyburger

Hilarious.. someone is going to ask why they aren't using a conveyor belt

Those who ask that question are relegated to only as an armchair project manager
In the time-lapse you can see the dirt move out quickly, the truck are not keeping up with the shovels and the flaggers (traffic control personnel) has no sit down time

[jollyburger]

Well the top sections looked like this



https://skyscraperpage.com/forum/showpost.php?p=9309154&postcount=1102

Marcon

Marcon collaborated with geotechnical engineers, structural engineers and the transit authority to fabricate large anchors to brace the guideway piers. Secants were installed around existing caissons and fixed to a temporary shoring wall during the excavation process.

https://marconmetalfab.com/our-projects/gilmore-place/

[jollyburger]

Also, I think the substantial work on the columns probably had more to do with keeping anything from moving while the columns are free standing during the excavation. You assume the guideways are just directly tied into the underground floors which would help with seismic support of the guideway..

[Lexus]

I'm really looking forward and 🞵🞵🞵🞵🞵🞵🞵🞵 if we may see a crane south of SkyTrain this year!

[Spr0ckets]

Originally Posted by Klazu

Not sure if this has been addressed before, but are SkyTrain column concrete slabs always this massive this deep into the ground or have they been continuously reinforced, as they went on with the excavation? It seems like total over-engineering to have them that bulky anywhere else than here.

I would have to imagine that extra reinforcement was done (and continuously being done) as excavation was ongoing, since, as you remove earth and dirt, you're essentially removing what the columns brace against to support the guideway (and themselves).

Probably the extra reinforcement is not just to compensate for the lost support, but also to help tie them to the project's own structural support system, which in turn is itself directly braced against the Earth, and transfers structural load onto it.

It's doubtful to me that they would have originally constructed them this massive and thick, since you don't really need that much structural support, when everything that's being supported is above grade.

There's probably some over-engineering (as is standard practice a lot of the time) but likely not much more so than you'd find for similar kinds of structures anywhere else in the world.
Engineers usually tend to over-engineer and over-compensate to provide extra redundancy in situations like this.


EDIT :I've also thought of some other reason they might have to rebuild them this massive.

Because the columns support is now essentially tied to the buildings' own support underground, could another reason be to reduce or buffer the inevitable extra live-load vibrations you'll be getting from skytrain cars running back and forth transferring to the buildings' own structure?

[jollyburger]

Originally Posted by Spr0ckets

I would have to imagine that extra reinforcement was done (and continuously being done) as excavation was ongoing, since, as you remove earth and dirt, you're essentially removing what the columns brace against to support the guideway (and themselves).

Probably the extra reinforcement is not just to compensate for the lost support, but also to help tie them to the project's own structural support system, which in turn is itself directly braced against the Earth, and transfers structural load onto it.

It's doubtful to me that they would have originally constructed them this massive and thick, since you don't really need that much structural support, when everything that's being supported is above grade.

There's probably some over-engineering (as is standard practice a lot of the time) but likely not much more so than you'd find for similar kinds of structures anywhere else in the world.
Engineers usually tend to over-engineer and over-compensate to provide extra redundancy in situations like this.


EDIT :I've also thought of some other reason they might have to rebuild them this massive.

Because the columns support is now essentially tied to the buildings' own support underground, could another reason be to reduce or buffer the inevitable extra live-load vibrations you'll be getting from skytrain cars running back and forth transferring to the buildings' own structure?

Yeah if you go back to the earliest photos it seems like there's only a narrow steel pile that goes down into the original concrete pier.

This thesis on new techniques for guideway construction has a ton of information (most of which I don't understand ) on Skytrain guideway characteristics

https://tspace.library.utoronto.ca/handle/1807/80907

I assume the original piers went down at least 100 feet because if it stopped further down you assume they would have had to do even more support work if they were excavating into an empty void below the column.

[Changing City]

Originally Posted by jollyburger

Yeah if you go back to the earliest photos it seems like there's only a narrow steel pile that goes down into the original concrete pier.

This thesis on new techniques for guideway construction has a ton of information (most of which I don't understand ) on Skytrain guideway characteristics

https://tspace.library.utoronto.ca/handle/1807/80907

I assume the original piers went down at least 100 feet because if it stopped further down you assume they would have had to do even more support work if they were excavating into an empty void below the column.

The image seems to suggest they excavated around, and down to the base of the original (previously underground) circular concrete foundation, then installed a ring of steel piles (presumably in bored holes) all the way round the original column to deepen the shaft supporting the SkyTrain. The middle (underneath the original pile) is presumably still the 'rock' that they're excavating, which looks like typical Lower mainland glacial till. The tops of those new steel piles were welded with the ring collar to keep them in place, and they added temporary braces between the collars and the walls to keep everything in place. They've created a new deeper column of a greater diameter incorporating the new vertical steel ring of piles. Once the parking levels are built there are presumably permanent walls in the parking levels that replace the temporary bracing, and hold everything in place - and once the buildings are built on either side it should all be as solid as if they hadn't excavated at all.

[Lexus]

Originally Posted by Lexus

I'm really looking forward and 🞵🞵🞵🞵🞵🞵🞵🞵 if we may see a crane south of SkyTrain this year!

And here it is!

2022, November 21

Untitled by Lexus LX600, on Flickr

Untitled by Lexus LX600, on Flickr

[CondoInvestor]

the third tower appears to be stuck, still on the same floor level for a while now

[Lexus]

Originally Posted by CondoInvestor

the third tower appears to be stuck, still on the same floor level for a while now

Seems that it took them 4 weeks to add 1 floor.

[RabidMoose]

I think they took what concrete they had and poured the other podium areas

Nov 24, 2022 - Some footings are starting to go in. I'm guessing I'm going to be looking at another crane on the left there.

[Klazu]

Such a great vantage point. Thanks for posting!

[djmk]

this project is wild.

[Coldrsx]

Fascinating, insane and pretty damn ugly.

[Metro-One]

Not ugly, but bland. The engineering is fascinating though.

[VancouverOfTheFuture]

Originally Posted by Metro-One

Not ugly, but bland. The engineering is fascinating though.

i am surprised that TransLink ever allowed them to do that to their columns. i had to deal with them on a project around some of their RoW, and man they were tough and i was not even coming close to this scale, not even 1% of this.

[Lexus]

South tower has only 3 floors left to go. Maybe after that one is completed they will move faster with east tower…

[Vantage]

Originally Posted by VancouverOfTheFuture

i am surprised that TransLink ever allowed them to do that to their columns. i had to deal with them on a project around some of their RoW, and man they were tough and i was not even coming close to this scale, not even 1% of this.

Was that on the Expo Line? Maybe the columns on the Millennium Line are a little beefier.

[Marshal]

Originally Posted by VancouverOfTheFuture

i am surprised that TransLink ever allowed them to do that to their columns. i had to deal with them on a project around some of their RoW, and man they were tough and i was not even coming close to this scale, not even 1% of this.

Translink would have been involved every step of the way (from the beginning, from conceptual through engineering working drawings phases) and would have dictated the design requirements and signed off on the engineering solution. They wouldn't have given any leeway to their guide-way specifications . . . so, they would have been 'tough,' but no tougher than any other project's structural requirements. This includes both the final product as well as the design of the false-work required during construction.

[jollyburger]

I mean just because they are uptight about their RoW doesn't mean they were any less on this project. If anything just because the fact it's so intricate would suggest they were even more overboard on monitoring/over-engineering everything.