CHICAGO | 1000M (1000 S Michigan) | 805 FT | 73 FLOORS - Page 75

Tom In Chicago · #**1481** Posted **Feb 17, 2020, 6:53 PM**

^Ah. . . that makes sense. . .

. . .

BVictor1 · #**1482** Posted **Feb 21, 2020, 7:10 AM**

02.19.20

bgsrand · #**1483** Posted **Feb 21, 2020, 2:17 PM**

Quote:

Originally Posted by BVictor1

02.19.20

why do some piers still have the steel sleeve on whereas others dont?

harryc · #**1484** Posted **Feb 23, 2020, 3:29 AM**

Feb 22

Chicago | 1000 S Michigan by Harry Carmichael, on Flickr

SolarWind · #**1485** Posted **Feb 27, 2020, 4:47 AM**

February 24, 2020

maru2501 · #**1486** Posted **Feb 27, 2020, 4:58 AM**

looks weird

KWillChicago · #**1487** Posted **Feb 27, 2020, 7:57 AM**

New technique?

Bombardier · #**1488** Posted **Feb 27, 2020, 11:17 AM**

^Not a new technique, but judging by the rebar projections this is going to be a thick mat slab. I would think we will see that placed in March based on current progress.

^^^^^Also, I'm not sure why some of the casings are not removed. They may have gotten stuck and had to be abandoned. Sometimes that will happen if concrete is poured up to the casing and left overnight. The next day when they go to take out the casing, they just can't get it out. Otherwise sometimes casings are permanent, but usually the design would call for several permanent casings (like at the property line when there is an adjacent spread footing at a neighboring building) rather than just one or two sporadically.

Donnie77 · #**1489** Posted **Feb 27, 2020, 1:15 PM**

Something seems off with this site...

harryc · #**1490** Posted **Feb 27, 2020, 1:53 PM**

Quote:

Originally Posted by Bombardier

^Not a new technique, but judging by the rebar projections this is going to be a thick mat slab. I would think we will see that placed in March based on current progress.

^^^^^Also, I'm not sure why some of the casings are not removed. They may have gotten stuck and had to be abandoned. Sometimes that will happen if concrete is poured up to the casing and left overnight. The next day when they go to take out the casing, they just can't get it out. Otherwise sometimes casings are permanent, but usually the design would call for several permanent casings (like at the property line when there is an adjacent spread footing at a neighboring building) rather than just one or two sporadically.

Case has a large frame with a massive block and tackle that is used for some of the more recalcitrant sleeves, even then they can't always get them back out.

bnk · #**1491** Posted **Feb 27, 2020, 6:04 PM**

Those piers look like they are crumbling.
I guess you get what you paid for.
I don't know how they would pass inspection.

Zapatan · #**1492** Posted **Feb 27, 2020, 6:11 PM**

^^ Agreed, looks like some ancient ruins

PittsburghPA · #**1493** Posted **Feb 27, 2020, 6:14 PM**

Quote:

Originally Posted by bnk

Those piers look like they are crumbling.
I guess you get what you paid for.
I don't know how they would pass inspection.

I believe that is limestone not concrete. It is very easy to remove so I'm guessing when they clean them up they will be spotless.

BuildThemTaller · #**1494** Posted **Feb 27, 2020, 6:41 PM**

Quote:

Originally Posted by BVictor1

02/06/17

Secondary mat:

Secondary mat with baby in the background:

This was from Vitsa's mat pour, the secondary mat. Perhpas we are seeing at 1000M the exposed tops of the piers that will go through and above the mat?

harryc · #**1495** Posted **Feb 27, 2020, 7:46 PM**

Quote:

Originally Posted by BuildThemTaller

This was from Vitsa's mat pour, the secondary mat. Perhpas we are seeing at 1000M the exposed tops of the piers that will go through and above the mat?

Correct

gebs · #**1496** Posted **Feb 27, 2020, 7:55 PM**

Published today:

1000M Construction Update

BUILDING A FOUNDATION
Over the past month, the team finished up the caisson installation. Now, attention turns to excavating the site and preparing to install the mat slab foundation, which will be the footprint for the entire building. The mat foundation will serve to distribute the building’s weight equally, reducing stress on the ground. The excavation is 4,500 cubic yards, goes down 11’6“ and will take two weeks to reach full exposure.

During excavation, McHugh is also exposing an area for installing the tower crane foundation. With that area secured, they can install reinforcement for the tower crane, which is essential before going vertical. The tower crane is slated to go up the second week in March, and will remain onsite for the entire construction process. In its first phase, the tower crane will only be about 188 feet in the air, and will continue to follow the height of the superstructure up to 800+ feet.

After excavation and tower crane installation, reinforcing the rebar and formwork is the next step. The top of the caissons will be exposed and using the tower crane, the team will install a layer of top and bottom reinforcing bars, creating a massive cage of rebar. But before the final foundational concrete can be poured, additional groundwork is needed.

Bombardier · #**1497** Posted **Feb 28, 2020, 12:21 AM**

Quote:

Originally Posted by bnk

Those piers look like they are crumbling.
I guess you get what you paid for.
I don't know how they would pass inspection.

What you are seeing is the sand they use to backfill the cage before putting the clay spoils/brick back of the top to use as a working surface as they continue drilling other caissons. The sand is easily removable with compressed air as it does not stick to the rebar. If they just put the spoils back in the hole they would have a lot of trouble cleaning the rebar before placing the mat slab. This is typical caisson construction for a high rise in Chicago.