Not too much new information on this one other than I guess I forgot about the old freight tunnels running under the site.


-No interior columns interrupting residential space
-3 outrigger locations
-tuned sloshing damper
-4’ x 4’ columns
-37’6” x 37’6” module bays

The damper on this one will be two stories, but seeing as things are still being designed, the capacity wasn't available.
https://im1.shutterfly.com/media/47a...D720/ry%3D480/

https://im1.shutterfly.com/media/47a...D720/ry%3D480/

https://im1.shutterfly.com/media/47a...D720/ry%3D480/

https://im1.shutterfly.com/media/47a...D720/ry%3D480/

https://im1.shutterfly.com/media/47a...D720/ry%3D480/

The scale on that one looks wacky.

^Yeah, it suggests that these things are somehow twice the height of BCBS and 25 percent taller than Aon. And it's not just a distorted perspective; they are actually rendered taller in relation to the horizon.

Any guesses when we will start to see them construct the crane base and mat floor? Possibly the end of the month/early march? Any chance this one will have two cranes?

Did the presentation confirm your other source's 893-foot height figure? I hope so!

nm (wrong thread)

I really enjoy the low rise buildings fronting on the park (specifically along Michigan), but I won't complain about more height and the southward march of the skyline.

The crown and dampening system are still being worked out in terms of design, but the tower will be between 887' - 893', which will still make it the tallest all residential (and tallest rental) building in Chicago when completed.

Feb 10




all together now - knocking the cage straight before lowering it.

The problem with slosh dampers is that, like almost anything else that contains liquid, they leak. And when they leak, they become a maintenance nightmare. When they become a maintenance nightmare, after many attempts at remediation, the owners give up and just empty them. Then there is no damping system. I worked for Vinoly on this project a little, (spent a year on the second tower though) and fought to have a viscoelastic system, which is basically a system of shock absorbers distributed throughout the structure, and for a while it looked as though they were going to do it, but then changed their minds.

Yes, exactly! check out this awesome video of that sort of dampener in action in NYC
https://www.youtube.com/watch?v=QJXThNHexJc

Very interesting.

Do most very tall buildings nowadays have a damping system of some type?

Or does it depend on the design and structure of the tower.

It depends on the structure and the use.

You probably won't find too many office buildings with dampening systems.

When it comes to residential, to prevent the sway and sense of motion sickness, you may have a dampener. The first tower in Chicago to use a dampener is Park Tower.

It also depends on the height-width ratio.

^ Damping. Not 'dampening'.

Wouldn't a liquid filled damping device also be a dampening device ?

^LOL, no sense in making any more jokes on SSP today! Harry wins! :notacrook:

Because of their larger floor plates, office buildings often use tuned mass dampers, which come in a variety of flavors. for example, the concrete block on a lubricated slab, which moves in the x-y plane to counter the movements of the building as it sways. there is also the suspended steel ball, which is basically a pendulum turned on its head. Then there is the slosh damper, already discussed. all of these slow down the acceleration of the building's sway, which is what causes discomfort in the building's occupants. Problem is, they occupy lots of space (2+ stories in some cases) and are expensive. The viscoelastic system I described earlier takes up very little space in each location, and is distributed throughout so as to absorb shocks where they occur locally instead of relying on a whole-building response. They are still considered somewhat experimental, which is why some building owners are reluctant to use them yet.

Any historical cases you know of where one of these devices worked improperly and amplified the buildings movement? I've always been curious about that.

I really hope the second tower is not built as designed. It looks like the height difference between 1GP and the second tower is 50ft at the most. That would be a disappointment. A tower at least as tall as Aon should be planned to balance out the southern and northern walls of Grant Park. The design should also be fresh and not recycle the 1GP design. I would love to see something like the shard in London with a diamond shaped top like Stone Container facing south east towards the Lake built at the Roosevelt/Michigan corner.

It will be disappointing if the field applied architectural treatment for 1GP is in fact just paint. This should be clad in metal, stone, or high quality precast not painted concrete.

What are slosh damper containers usually made of? Would welding pieces of metal together to create the container not make it sealed against leaks? Also what are your thoughts on the tuned mass damper for Taipei 101?