What's going on here? There is nothing permanent about this.

What do you mean? They are building the climbing form assembly for the core. This is totally temporary and features reusable forms that open and close to allow workers inside to place the rebar before closing back up and being filled with concrete.

Thank you. I knew it was temporary I just didn't know its function. Now I do.

^Understandable. Looks permanent because the formwork is shiny and new. Typically, they're orange and rusty but the problem is that GCs don't have any old ones lying around in their equipment yards thanks to the most tremendous construction boom in Chicago history! They're all spoken for! :cheers:

So much respect for these construction workers. Not only do they work in dangerous and precarious situations, now it's the weather. The guy above is doing something with that 2x4 while balancing on minimal foot support all while carrying a cumbersome tool belt and safety harness. :worship:

November 15, 2019

awesome pics. can't wait to watch these two massive elevator cores rise above LSD

Because of the three cranes working together do the two towers have to rise simultaneously level for level?

Since all 3 cranes are luffers, they have a lot of flexibility. I would expect that we will always see the taller one jump first and the medium one jump second. The towers should rise roughly floor for floor once the climbing cores are both built (barring unforeseen issues). The small crane is probably at it's ultimate height since it is only there for a short time to support the podium.

Nov 15

Nov 20

How cool would it be if both buildings shared the same slab for each floor. That would be so huge taking up the whole site and fun to watch.

Wow. Stellar shots, Harry. Gracias

Is that a big ass crack in the concrete?

Thank god for rebar.

Tensile. Should be fine.

More likely some squeezed between the forms - which would be joined right here.

Nov 27

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

At the rate that they're going I feel like this is almost finished, lol. They literally broke ground 13 weeks ago.

Its good for the haste!!!! get these infill towers built so that the larger site I can commence!!!

Haha, my thoughts exactly. If feel like these two towers are basically part of Site I's construction in that sense.

December 3, 2019

looks like Navy Pier is finally getting its glass!

Dec 4

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

December 3, 2019





December 7, 2019

Such a much needed gap filler from that last view. I just hope site I doesnt get a height chop.

A couple sick photos from @suicide.shots

https://i.imgur.com/nHpuf1dh.jpg

https://i.imgur.com/NBKNbWBh.jpg

Dec 11

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Climbing form
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Under construction
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Post Tension
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

December 17, 2019

Honest question -- why is it these towers seem to be rising so much faster than One Chicago, which started earlier?

they are smaller

Thats going to be such a massive mat pour when the two are connected.

At one Chicago, the contractor installed a secant wall around the entire city block and excavated the entire site 15'-20' below grade. They also dug cores down 50' below grade with complex cofferdams before starting to come up. The underground construction of One Chicago is orders of magnitude more complex.

exciting to see it already rising

One Chicago needs to go down before it goes up, this one starts at grade.

the floor plates are already being done in sections. The mat pours were done a month or so ago.

Oct 16 2019

Form work going up for the mat.

Thanks! Exciting the buildings have different timelines--we'll get to see some cool construction for quite a while.

These look to be 2 very standard residential towers - with a shared large podium. This will be a great contrast to One Chicago which has secant walls, top down construction, and many levels of underground parking - next to an active subway station.

My bad Harry. I meant the floor plates stretching across the whole site for the big ass podium. Am I right in thinking the floor plates are going to be even for majority of both buildings throughout the podium? Possibly the towers as well?

Ah, yeah you are right but they stagger the work they wouldn't pour an entire floor at once

Watch this starting at 5:13: (Extreme Engineering) Build It Bigger - High Risk Tower (S02E10).mp4

Dec 20

Thanks Cozy. I love when you guys post informative videos for us novice scraper lovers.

My pleasure. I'm learning alongside the rest of you :cheers:

I developed an understanding of staggered construction watching Vista tower go up. Talk about massive floor plates.

As I was typing out an explanation I remembered that scene in Trump Tower Build It Bigger, I love those construction docs. Was a better use of my time to link you to it :tup:

This site is definitely worth seeing in person, esp. since you get since a nice view from above

December 24, 2019
https://live.staticflickr.com/65535/...9aa18f85_b.jpg

Not for long :haha:

Is that the max height for the short crane?

You have to assume that it is. Jumping a crane is expensive so they would have set that crane to its ultimate height when it was originally set up. It is only servicing the podium not either of the towers, so I think that is all the higher it is going.

Dec 27

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Note the termination of the post tension tendons in the lower right.
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr


Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Climbing Forms
 

This site give excellent views of the climbing forms

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

A roomy gallery to work in - and a dedicated pad for crane deliveries.
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Outer forms pulled away
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

The top of the core just after the forms have been raised.
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

The rollers that the outer part of the form hangs on.
Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Chicago | Cirrus and Cascade by Harry Carmichael, on Flickr

Construction question: In the pic above, why is some of the rebar coated and some is not?

Generally the vinyl coated rebar is used in parking garages and other areas where heavy salt use is expected.