CHICAGO | Highrise Projects & Construction, v7 - Page 595

SolarWind · #**11881** Posted **Jul 4, 2018, 12:18 AM**

July 3, 2018

the urban politician · #**11882** Posted **Jul 4, 2018, 12:58 AM**

Quote:

Originally Posted by SolarWind

July 3, 2018

“Where do we put the caissons?”

PittsburghPA · #**11883** Posted **Jul 4, 2018, 2:06 AM**

Great shots SolarWind! Can anyone shed any insight on the foundation work for Union West? It doesn't seem as if it's a typical caisson project like most of the other projects going on right now.

I saw they were pounding steel beams through the clay, do they drive them to bedrock instead of the reinforced concrete caisson?

harryc · #**11884** Posted **Jul 4, 2018, 3:47 AM**

Quote:

Originally Posted by PittsburghPA

Great shots SolarWind! Can anyone shed any insight on the foundation work for Union West? It doesn't seem as if it's a typical caisson project like most of the other projects going on right now.

I saw they were pounding steel beams through the clay, do they drive them to bedrock instead of the reinforced concrete caisson?

Those are piles - they support the building by the friction on the sides of the piles, not by bearing load on the bottom. A mat will be tied in to the whips you see welded on top of the piles. The "normal" caisson work is piers - the load is supported by pressure on the bottom of the pier, this is why they use the belling bits, to spread out the area that bears the load. In Chicago piers traditionally go ~60' to hardpan, the piles are used when the hardpan is too far down (?). For really heavy loads the piers go all the way to bedrock.

Bombardier · #**11885** Posted **Jul 4, 2018, 4:31 AM**

Wow, Union West... didn’t realize that was getting a basement and significant earth retention!

PittsburghPA · #**11886** Posted **Jul 4, 2018, 4:39 AM**

Thanks, Harryc! I appreciate the explanation

KWillChicago · #**11887** Posted **Jul 4, 2018, 4:56 AM**

When is K2's brother supposed to start? Also known as 352 N. Union I believe.

Randomguy34 · #**11888** Posted **Jul 4, 2018, 6:06 AM**

Quote:

Originally Posted by KWillChicago

When is K2's brother supposed to start? Also known as 352 N. Union I believe.

A revised application was approved by the plan commission last week, so that's a sign the project isn't dead.

Speaking of which, July's agenda has been posted. Only two highrises are listed, 310-328 N Sangamon and the Equinox Hotel.
https://www.cityofchicago.org/conten...018_Agenda.pdf

harryc · #**11889** Posted **Jul 4, 2018, 1:25 PM**

July 3

Mr Downtown · #**11890** Posted **Jul 4, 2018, 5:46 PM**

I was surprised to learn that piles sometimes go to bedrock; the foundation guy at 14th & Wabash told me they were hitting dolomite at -95. Indeed, you could hear the sound change and see that no more progress was made with each hit. Since the steel beams weren't actually that long (probably 75-footers), they drive them until about three feet are sticking out, and then a welder uses plates in the web and prodigious amounts of bead to join another beam directly on top, end-to-end. The driver comes back and does another 20 feet, and then the welder cuts off the remaining beam/pile a foot or so above ground level.

I think the spec is usually "driven to refusal," and I guess in some places the soil is so sandy that that isn't reached until bedrock.

ardecila · #**11891** Posted **Jul 4, 2018, 5:55 PM**

I'm curious about the decision of piles vs. caissons in Chicago projects these days. The load capacity of a caisson is probably much higher, so you can probably sink fewer caissons vs. piles and get out of the ground faster. There's also less noise/disruption to neighbors with drilled caissons vs. driven piles.

But with the ridiculous building boom going on, it seems like some developers are looking at the cost premium for caissons (or the waiting time to get equipment) and deciding they'd rather go with the slower process of driving piles.

harryc · #**11892** Posted **Jul 5, 2018, 12:27 AM**

July 2

July 3

harryc · #**11893** Posted **Jul 5, 2018, 2:54 AM**

July 2

SIGSEGV · #**11894** Posted **Jul 5, 2018, 3:59 AM**

harryc · #**11895** Posted **Jul 5, 2018, 9:08 PM**

(and some Gr333n on the left)

gebs · #**11896** Posted **Jul 5, 2018, 9:43 PM**

Quote:

Originally Posted by harryc

(and some Gr333n on the left)

With all the development in the West Loop and Fulton Market, the canyon-ization of the Kennedy, and the potential for a K3-type high-rise, it might only be a matter of time before Carnivale (pictured above, center) gets swallowed up by the development maelstrom.

Which would be fine for most people. But I got married there. So that'd be a little sad for me.

SolarWind · #**11897** Posted **Jul 6, 2018, 1:09 AM**

July 5, 2018

PittsburghPA · #**11898** Posted **Jul 6, 2018, 4:03 AM**

Quote:

Originally Posted by KWillChicago

When is K2's brother supposed to start? Also known as 352 N. Union I believe.

Everyone with a south facing view in K2 will be none too happy once that one rises.

k1052 · #**11899** Posted **Jul 6, 2018, 12:23 PM**

Quote:

Originally Posted by PittsburghPA

Everyone with a south facing view in K2 will be none too happy once that one rises.

The beauty of rentals is that one can, eventually, move if unhappy with the situation. Also most apartment dwellers don't seem to subscribe to the idea that nothing should ever change once they take up residence...unlike a lot of condo owners.

The Lurker · #**11900** Posted **Jul 6, 2018, 8:17 PM**

Quote:

Originally Posted by PittsburghPA

Everyone with a south facing view in K2 will be none too happy once that one rises.

What a pity they'll lose their view of congestion on the Kennedy