CHICAGO | 400 N Lake Shore Drive | 851 FT & 765 FT | 73 & ? FLOORS - Page 131

Klippenstein · #**2601** Posted **Nov 2, 2024, 7:10 PM**

Wow! Very interesting to see the footprint of the building take shape.

cmrhm · #**2602** Posted **Nov 2, 2024, 9:43 PM**

I would like to know where is the tower portion floor plate outline, does anyone knows?

CCRC · #**2603** Posted **Nov 3, 2024, 3:18 AM**

In recent photos, It looks like they are doing site Prep for Tower II

BrickellBased · #**2604** Posted **Nov 3, 2024, 8:39 AM**

Quote:

Originally Posted by CCRC

In recent photos, It looks like they are doing site Prep for Tower II

If you're referring to the caisson rigs in the photos Chicago Yimby mentioned it is likely due to the need to modify existing the foundation elements

https://chicagoyimby.com/2024/10/constru...-shore-north-tower-in-streeterville.html

Quote:

Caisson equipment has returned to the site, perhaps related to a pending permit with the City of Chicago for “revision of select caissons from belled to T.O. rock due to conditions encountered on site.”

bhawk66 · #**2605** Posted **Nov 3, 2024, 2:43 PM**

Quote:

Originally Posted by BrickellBased

If you're referring to the caisson rigs in the photos Chicago Yimby mentioned it is likely due to the need to modify existing the foundation elements

https://chicagoyimby.com/2024/10/constru...-shore-north-tower-in-streeterville.html

Well, gee, thanks for the "nothing nugget" of info, lol

Even AI has no idea, haha

What does T.O. rock mean in construction:

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It looks like there's not much info available about T.O. rock in construction, but here's some related information about rocks used in construction:

ardecila · #**2606** Posted **Nov 3, 2024, 4:09 PM**

T.O. is "top of". Common abbreviation in construction.

Some of the original caissons were belled - implying that they bear on clay (either soft clay or hardpan) and they need a wider base to spread the load. In some cases, where the caisson needs to bear a very large amount of load, they can drill deeper down to the "Top Of" bedrock, or in some special cases they will actually drill a few feet further for a "rock socketed" caisson. This is what the supertall buildings use, and 400 LSD actually has a few rock-socketed "super caissons" left over from the Spire.

However, due to the new tower footprint they had to drill a few new caissons in addition to reusing the old. It sounds like they started with belled caissons on hardpan, and they failed the load tests - hardpan wasn't so hard after all. So they are gonna drill deeper down to rock. Sucks for Related, this could be a massive change order.

BrickellBased · #**2607** Posted **Nov 3, 2024, 6:46 PM**

Quote:

Originally Posted by ardecila

T.O. is "top of". Common abbreviation in construction.

Some of the original caissons were belled - implying that they bear on clay (either soft clay or hardpan) and they need a wider base to spread the load. In some cases, where the caisson needs to bear a very large amount of load, they can drill deeper down to the "Top Of" bedrock, or in some special cases they will actually drill a few feet further for a "rock socketed" caisson. This is what the supertall buildings use, and 400 LSD actually has a few rock-socketed "super caissons" left over from the Spire.

However, due to the new tower footprint they had to drill a few new caissons in addition to reusing the old. It sounds like they started with belled caissons on hardpan, and they failed the load tests - hardpan wasn't so hard after all. So they are gonna drill deeper down to rock. Sucks for Related, this could be a massive change order.

Thanks for the explainer.

How do they fix caissons that are already 100+ feet underground? Or do they just have to drill new ones?

BrickellBased · #**2608** Posted **Nov 3, 2024, 6:50 PM**

Looks like they are (re)working in the area near where they were drilling in March at the top of this photo from Solarwind.

post https://skyscraperpage.com/forum/showpost.php?p=10171359&postcount=2434

ardecila · #**2609** Posted **Nov 5, 2024, 1:03 AM**

Quote:

Originally Posted by BrickellBased

Thanks for the explainer.

How do they fix caissons that are already 100+ feet underground? Or do they just have to drill new ones?

That’s the million dollar question! There is no single method, it is highly dependent on the specifics of each situation.

in this case I assume they would drill right next to the faulty caisson and add some kind of transfer mat or pile cap to make it line up with the column above.

BVictor1 · #**2610** Posted **Nov 15, 2024, 11:32 PM**

11.09.24

11.10.24

BVictor1 · #**2611** Posted **Nov 22, 2024, 3:36 AM**

11.20.24

lakeshoredrive · #**2612** Posted **Nov 23, 2024, 12:45 AM**

Woo hoo! Officially above ground!

PittsburghPA · #**2613** Posted **Dec 13, 2024, 8:50 PM**

I was driving north on LSD today and the form work for the core is at the level of LSD. If I had time I would have stopped to update with some pics. Can't wait to see an update on here hopefully soon.

Cress3803 · #**2614** Posted **Dec 13, 2024, 9:36 PM**

curious where this will sit looking in from angles to the west. I have tried to judge using Vista but not sure how much Trump will block if from, say, Wicker park etc

BVictor1 · #**2615** Posted **Dec 13, 2024, 10:50 PM**

As and you shall receive...

Quote:

Originally Posted by PittsburghPA

I was driving north on LSD today and the form work for the core is at the level of LSD. If I had time I would have stopped to update with some pics. Can't wait to see an update on here hopefully soon.

12.13.24