O-Train Line 2/4 [Stage 2 | Greenboro to Limebank/Airport] | In Service

[Kitchissippi]

It almost looks like they're building the Rideau Canal as it was first intended if John LeBreton hadn't been too greedy

[Harley613]

Hopefully someone with more knowledge of the equipment can decipher what is happening here today:

above2 by harley613, on Flickr

above by harley613, on Flickr

[Harley613]

Some quick google sleuthing and it looks like OCCheetos is correct, they are making Caissons with a Caisson drilling rig. I can't imagine them building the pedestrian bridge before the first phase, it would be a bridge to nowhere. There is also no sign of site prep on the opposite side of the tracks. I am hoping the Caissons are related to the first phase of Trinity Station itself.

[Catenary]

Originally Posted by Harley613

Some quick google sleuthing and it looks like OCCheetos is correct, they are making Caissons with a Caisson drilling rig. I can't imagine them building the pedestrian bridge before the first phase, it would be a bridge to nowhere. There is also no sign of site prep on the opposite side of the tracks. I am hoping the Caissons are related to the first phase of Trinity Station itself.

My feeling is that these are for the bridge. I've never seen a condo/tower that started with cassions, they almost all start with excavation for parking or driving piles for support. Cassions to support the bridge make sense to do first here if you consider that access to this side of the site will be difficult once excavation begins.

Though the bridge will be connected to the building, it's not uncommon to have pedestrian bridges supported independently of the structure, as it simplifies design. Distinct foundations separate the building and the bridge and lead to shorter spans and easier installation of the bridge.

Finally, the bridge is labelled "by others" on the Trinity site plan, so it is likely the responsibility of OC Transpo and either part of the stage 2 contract or being prepped now for later installation.

Originally Posted by OCCheetos

Here's the site plan [rotated] for reference:



I guess it really depends on where they start drilling, but right now that machine is not where the pedestrian bridge will be. ¯\_(ツ)_/¯

Edit: Maybe I'm just out of the loop, but what exactly are the references to "Richmond Street", "Loretta Avenue", and "Champagne Avenue" on the site plan supposed to be for? They're nowhere near the site.

They have laid gravel out to the corner of the site closest to Bayview and there's nothing there right now, so I'm guessing that is where the work will be. This is roughly where the bridge is, you can see a new sanitary manhole there just north of the gravel in the overhead shot, and this lines up with the "Connection to existing sanitary" labelled on the plans.

As for the roads, this area is a grid so they were likely all surveyed originally. Because of the railways and Wellington on an angle as a forced road, many of the roads would never have been opened, but they appear on the plans.

In particular, Champagne is now City Centre, and it was only renamed fairly recently to make it distinct from the southern portion of Champagne. The self storage facility is the former Champagne streetcar barn, and OC Transpo referred to the bus layup on the north side as Champagne Layup up until it's closure last year.

Loretta Avenue exists south of the site, and is the next street west of Champagne. It would run right through the site of it were to exist.

As for Richmond, I believe this is what is now Bayswater, except Bayswater ended up with a swing to the west. It was likely renamed to avoid duplication too, but much earlier.

[Marcus CLS]

Originally Posted by OCCheetos

Here's the site plan [rotated] for reference:



I guess it really depends on where they start drilling, but right now that machine is not where the pedestrian bridge will be. ¯\_(ツ)_/¯

Edit: Maybe I'm just out of the loop, but what exactly are the references to "Richmond Street", "Loretta Avenue", and "Champagne Avenue" on the site plan supposed to be for? They're nowhere near the site.

A good point of reference is the existing Fiber Optic shelter as it is on the site plan and Harley613's overhead shot. By comparison the location of the caisson being drilled is almost straight north of (right on image) and on the production of the East limit (bottom limit image) of the existing shelter. It is difficult to scale distance but I put the caisson being drilled on the site plan somewhere between Tower 1 and Tower 2 but closer to Tower 2 on Trinity Land. Have fun guessing why they are drilling at that location.

[Marcus CLS]

Is Aecon a partner of the trillium line consortium? Clearly shown on red container.

[OCCheetos]

Originally Posted by Marcus CLS

A good point of reference is the existing Fiber Optic shelter as it is on the site plan and Harley613's overhead shot. By comparison the location of the caisson being drilled is almost straight north of (right on image) and on the production of the East limit (bottom limit image) of the existing shelter. It is difficult to scale distance but I put the caisson being drilled on the site plan somewhere between Tower 1 and Tower 2 but closer to Tower 2 on Trinity Land. Have fun guessing why they are drilling at that location.

Yeah, that's why I'm wondering whether they're actually drilling where that drill is located, or if that's just where it was being kept after they set it up.

Originally Posted by Marcus CLS

Is Aecon a partner of the trillium line consortium? Clearly shown on red container.

TNEXT is 100% SNC Lavalin, but they've been subcontracting. So far I've seen Pomerleau and Tomlinson equipment around, but I don't think I've seen Aecon yet. Can't rule it out though. Maybe Catenary knows?

[Marcus CLS]

[QUOTE=OCCheetos;9081043]Yeah, that's why I'm wondering whether they're actually drilling where that drill is located, or if that's just where it was being kept after they set it up.


I think your right. It is just parked there. Nothing has been drilled yet. Nevermind.

[OCCheetos]

Sure enough, I went by tonight and it's been moved to that other gravel pad where the bridge is supposed to end and it's ready to drill.

I wasn't able to get any pictures that show where it is very well, and it's hard to take any pictures at night facing east because they have some really bright floodlights, but

Full size:
https://i.imgur.com/u9ONaYj.jpg
https://i.imgur.com/9jSJGfT.jpg

[Catenary]

Originally Posted by OCCheetos

Yeah, that's why I'm wondering whether they're actually drilling where that drill is located, or if that's just where it was being kept after they set it up.



TNEXT is 100% SNC Lavalin, but they've been subcontracting. So far I've seen Pomerleau and Tomlinson equipment around, but I don't think I've seen Aecon yet. Can't rule it out though. Maybe Catenary knows?

I see you went and saw that they moved. I'm guessing they just setup where they did for easier access.

I haven't heard of Aecon doing any work, but it doesn't surprise me. Unlike KEV going east/west, SNC is an engineering firm/general contractor, they have virtually no construction resources of their own so everything is contracted. Aecon has a strong local presence through their purchase of Karson a few years ago, and although they do a lot of projects on their own they are frequently a subcontractor as well.

[Harley613]

I walked by this evening and still can't really tell what's going on.

20201024_174136 by harley613, on Flickr

[acottawa]

The white drill looks like it is taking rock or soil samples. I have no idea what the orange pipe or the larger drill is for.

[Harley613]

I've been racking my brain for days trying to remember where I saw something like this before, and I finally got it! Read the highlighted text below from the 9 Dekalb thread in 2017! It's the exact same scene at Trinity Station as in the picture, same machine and caisson molds. Based on where the site trailer is at Trinity and where they are working I am now fairly confident that the 65 story tower is under construction.

Capture by harley613, on Flickr

[eltodesukane]

I saw similar at "The One" in Toronto.
https://urbantoronto.ca/forum/threads/to...elopments-foster-partners.18167/page-352

[Harley613]

Yeah I can't see those massive caissons being drilled for a simple pedestrian bridge, unless they are planning to move a lot of elephants across it. There's no way. These are skyscraper sized.

From this website:

https://www.foundationstructures.com/the-benefits-of-caisson-drilling/

What is Caisson Drilling?
Caisson drilling is a specific style of creating structural foundations by which boreholes called caissons (sometimes called drilled piers because of their cylindrical shape) are drilled into the ground and then filled with concrete and reinforcing materials. The main goal of this method is to reduce the potential for vertical movement caused by soil settling in order to avoid the structural damage that could otherwise result.

Traditionally, flat, horizontal, floating foundations have been used to evenly distribute the weight of the building above. However, uneven settling could lead to all kinds of problems including leaning, cracked foundation and structural elements, and even eventual collapse.

With caisson drilling, weight-bearing concrete columns (perhaps supplemented by steel cages or other reinforcements) can reach all the way down to the bedrock, providing for a much more stable base for large structures.

This method of building foundations is not necessary for every structure – the average home is unlikely to use caissons. However, this style of creating structural foundations is preferable for larger, taller buildings, and especially high rises, for the purposes of safety, longevity, and structural integrity.

[Richard Eade]

So, no-one remembers all of the caissons that went in for the (relatively) small Bayview Station?



Caissons can also be used any time there may be unstable ground - such as ground that has been dug up several times to bury, then move, large sewer or water pipes. When these piers are run down to bedrock, there is more assurance of a stable foundation.

What we are seeing, could be the start of the podium area where the bridge to the Bayview Station would launch from - or it could simply be a stable footing for the end of the bridge, itself. Remember, all of the piers holding up the LRT's guideway are also this type of drilled caisson pier.

[Richard Eade]

As far as what you are seeing with the “big orange pipe”, this image gives a good idea:



The pier does not have to be supporting a high-rise tower. It is just providing a stable point. To form the pier, a hole is drilled (often down to bedrock, if high loads are to be supported); then a ‘cage’ of reinforcing metal is added into the hole; which is then filled with concrete.

In cases where the ground may not be stable enough to support a clean bore of the depth required, a casing (the “big orange pipe”) can be pressed down into the ground, and then the material cleaned out from inside the casing with an auger. If the hole needs to be deeper, (to reach bedrock, for example) then additional lengths of casing can be welded on and the entire casing is pushed down further.



Once the concrete is poured, it can be completely cured in the casing, resulting in the casing becoming part of the pier. In this case, the casing is sacrificed. Alternatively, if it is feasible (likely because the length of the casing is less than the lift height of the rig), the concrete can be left to partially set and then the casing can be pulled out of the hole, to be re-used. Without the casing, the concrete will slump somewhat, but its outward pressure will hold-back the sides of the bore from collapsing.

[harls]

Originally Posted by Richard Eade

The pier does not have to be supporting a high-rise tower. It is just providing a stable point.

Aw Richard...

[Harley613]

Originally Posted by Richard Eade

So, no-one remembers all of the caissons that went in for the (relatively) small Bayview Station?

I don't because I am learning as I go here but I see what you mean. It could be a big anchor for the end of the pedestrian bridge. The suspense is killing me haha.

[J.OT13]

Rail613 posted some pictures of Stage 2 Trillium. They've removed the rails and platforms at Greenboro and Mooney's Bay, but otherwise it looks the same, so not worth posting.

Walkley:




https://twitter.com/rail613/status/1320796604304101377

South Keys:




https://twitter.com/rail613/status/1320794386989522945