Elevator pit slab lowering

[pond68]

A contractor is facing a problem with elevator pit slab poured. The slab was poured 10" higher and now he need to remediate that problem. Also note that the pit wall is already poured & 3 story cmu elevator chase wall constructed on top of the wall.

What's the best to fix that problem without undermining the cmu chase wall?. He needs to cut the slab & have it poured at 10" lower.

 

[msquared48]

I would jackhammer out the existing slab, trying to save the wall steel stub bars as much as possible, and re-configure the wall steel stubs after the proper elevation is reached to maintain the integrity of the connection, pouring the new slab after that.

May have to do this in a segmented underpinning mode to preserve the integrity of the CMU wall above, as in one side at a time so the wall can span over the voids created.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[csd72]

If the supported loads are not too excessive then you could needle through the CMU wals and support them on props away from the ahft.

You then will have relatively free reign on what to do with the pit.

 

[Brad805]

Wow, big mess up. I dont' suppose there is a different elevator option? We have been involved in elevators that require differing pit depths. I would talk directly to the elevator company to investigate other options first. I bet you could almost double the elevator cost and still walk away saving the GC money.

Brad

 

[pond68]

csd72... Can you please explain a bit more your option?