The caisson drills are on site, but I don't think anything has been drilled yet.

http://i.imgur.com/w6e6W.jpg

http://i.imgur.com/Z1w9u.jpg

http://i.imgur.com/m8oh8.jpg

Dec 17
 

Mounting a caison drill..


Some serious belling bits.


Drilling underway, sump hole ?




Many more photos from 435 Park, Chicago Ill.

From Lynn Becker's blog:

• Video Link

This one is very much under construction now, can we move it out of proposals?

so this bad boy is now officially under construction.

time to move the thread. :cheers:

Pretty rad, thanks for posting. If the glass is kosher, the views from Michigan Ave will be impressive, even if the design is a bit tacky.

btw, Lynn Becker is reporting height of 590 feet.

now that it's actualy UC, is there a final tally on what is going to be in it and where? One restaurant? Any shopping? and is it officially classified mixed use?

12-26-2012
 

435 Park so far
465 Site Prep from 2007

Jan 2 & 4 - 2013
 

Progress now for the future - don't know why this makes me think of DEVO


Safety first - when did these fences become standard ?


We have struck Clay !


This is how the monsters get out ...




More 435 N Park

Mark me down as very happy to have been wrong (too skeptical) about this one! Nice way to end 2012 with this start. I have the same question someone else did recently - do we know that the official height is 635'? Only as I had also seen 590' quoted elsewhere too......

Lynn Becker has a handful more of contruction photos. Some pretty interesting night shots that do a really good job of giving a sense of scale.

I took this picture at a community meeting in March. The renderings of the building have changed slightly since that meeting, so I am not sure if the exact heights have changed, but this is at least someplace where some of these numbers may be coming from.

Here is another photo of the night construction. I am actually really surprised they are able to work so late into the evening. They are working with those big flood lights until at least 7pm if not a later every week night. Not to sound NIMBY-ish, but if I lived in one of the low rise condos and was trying to eat dinner or relax after work at 7pm and still had flood lights and drill rigs going outside, I would be kinda annoyed. Anyone have insight into this?

Oops:

https://lh5.googleusercontent.com/-C...s912/photo.JPG

^That's awesome. Maybe they're making maximum use of the mild temps?

Makes sense. I wonder what the OT pay out would be or maybe its multiple shifts (early crew/late crew)?

435 N Park and Optima Center
 

http://farm9.staticflickr.com/8372/8...5cb05ece_b.jpg
435 N Park site and Optima Center by YoChicago1, on Flickr

Shot earlier today. As always, larger versions at Flickr.

Jan 10
 

\
Looks are decieving - probably a dozen or more pilings(?) have been drilled/poured/and buried already.

Odd the way the lower(?) section has 3 times the bands the upper section has, and then it just stops - is this the section that is inside the belled out area at the bottom ?


Putting in the electric service - hope they don't forget about this when the sheet pile guys come around ;-)


Chocks to space the rebar - inner sleeve - and outer sleeves


You could feel the concrete as it hit bottom some 60' (?) below

This may be too much detail, but here goes...

The portion with the increased reinforcing is most likely the top. All Caissons will have at least a portion of the top of the shafts reinforced (usually a minimum of 20 feet down). This is because caisson shafts are basically big concrete columns that are in compression and need rebar to help confine the concrete as it takes the load. Caissons that are only taking gravity loads (down only, not wind) only need the confining reinforcing for part of the shaft because as they get deeper the soil can trusted to help confine the concrete.

This caisson, with the increased rebar at the top, is probably part of the buildings lateral system (i.e. wind resisting system). Because of this there is a horizontal load that is introduced into the foundation causing the shaft to not only be compressed, but also bend and shear. The bands of reinforcing, called stirrups, are probably tighter at the top because of the higher shear forces. Sometimes when a caisson is taking bending the reinforcing is extended for the entire length of the shaft for simplicity and robustness. However it is possible to calculate the location down the shaft where the bending forces are dissipated enough to rely on less reinforcing or even the unreinforced concrete alone.

Sorry for the nerd explosion...:tup:

Thank you ! that is exactly the level of nerd explanation I was looking for.

Jan 15 2013 - foundation work continues.
 

Case working North with the grid of holes - needed to move the sleeves to put in holes on that side.


Some going out


Some being re-located



465 N Park - Site prep to today