I've always wondered this too. Whether these beams are permanent or temporary.

Bracing like that is nearly always temporary, the slab of the parking garage takes up the stress that the bracing bears rendering them useless once the floors are constructed.

Once poured and cured the floor takes the load the beams are bearing now - they will be removed.

From the building of 353 N Clark - Meserow - 10yrs ago. After pouring the floors around the beams the beams are cut out and the holes in the floor and wall filled in. With the WP supports running dead horizontal this should be much easier.

Park Tower in San Francisco had a similar shoring system which consisted of cross bracing. You can see in the images below the bracing piece was lifted out and you can see the previously poured slab below. The pictures Harry posted are of rakers which are left in until the below grade portion is constructed due to them holding up the entire wall from one point, where as with cross bracing the hole is braced so that once each level is poured the bracing can be removed. Keeping the bracing in until after the below grade portion is constructed isn't unheard of, just uncommon.

https://i.imgur.com/JzBpDwj.jpg
https://i.imgur.com/Dtzj0bk.png
Oxblue -- https://app.oxblue.com/open/clarkconstruction/block5

^^ interesting stuff, thanks!!

Anyone know when this tower is scheduled to get off the ground and finish foundations work?

I'm sorry but shit like this blows my mind. Not only is it supporting a main river branch but also one of the biggest lakes on the planet.

Are you talking about the support beams? They do indeed help brace the excavation site from the river, but not necessarily the lake. The lock system at the mouth of the river is what really holds the lake in, more or less, as the lake is (usually, depending on weather conditions) several feet higher than the river.

That makes sense. I wasn't thinking about the lock system. Do they re-use those beams or are they sized per site then disposed of?

Also, whats the difference or determination between using angled beams or straight/horizontally placed beams? I would imagine it would have something to do with near water location or soil quality?

The sheet piles are usually kept in and the walers (the beams that run along the wall and distribute the load) and bracing and reused.

Walsh is definitely into re-use.

I really hope they keep that temporary bridge/riverwalk lol, for WPS. Engineering phenom. And thank you all for your intelligence and insight. Especially for an amateur skyscraper nerd such as myself. Keep the info coming.

Here's from my office.

http://i51.photobucket.com/albums/f3...pslpsuqevh.jpg

Wow, thank you. the engineering here is really stellar.

I just wish this was going to look a bit more iconic there along the river. Something like this announced project in Hamburg:

http://forum.skyscraperpage.com/showthread.php?t=232028

That gradual sloping of tower into base could do a lot of good for Chicago, given its recent (well, the last 40 years or so) explosion of towers-on-podiums.

I agree, the skyscraper nerd in me loves watching it go up, but this development is a lost opportunity on the whole.

Feb 6





Feb 5

Great shots, Harry! Especially love that last one. Really shows the growth of the north branch river canyon we've had in the last decade or so. I wonder how long until its impressive enough for Chicago river boat tours to start sailing up on it? :)

uh, they already do…