RC stairs with or without column? 2

[mats12]

Hello, I'd like to ask about concrete stairs.
Is it possible to make it work without a column as shown bellow?
All walls are masonry walls so no cantilever action there.

 

[jayrod12]

Theoretically anything is possible, but the member sizes required to make this work will be gargantuan, and the stiffness required at the top to resist the loads imparted at the top of the stair is high and therefore hard to get to work with standard framing.

You could look at having a cranked slab from that mid-height landing down to the floor, still need to find a way to support the stair at the top.

 

[KootK]

I'd think that this would be okay without the columns unless those are giant ogre steps.

 

[MIStructE_IRE]

My thoughts exactly Koot. That’s how we’d normally tackle it even with masonry walls.

 

[dik]

Like this?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Menai]

There is an old form of construction, known as a pencheck stair, which can be used to support a stair from a masonry wall without columns. Such stairs appear to ‘cantilever’, but as inferred by the original question, they do not do so. Pencheck stairs work by combined bearing and torsion and were originally constructed from stone; so no issues with concrete.

I have conserved several examples in old buildings. You can find an explanation of how pencheck stairs work at the web address below.

https://load-paths2020.blogspot.com/search?q=Pencheck

Good luck with your design.

 

[mats12]

@Kootk - thats what I had in mind when looking at it. I have the same dillema about upper slab.

@Menai - great article! tnx

Thanks for help everyone.

 

[HTURKAK]

Yes.. If the masonry walls are load bearing type.. This is still a valid detail at some regions. The precast landings and steps fixed to the masonry wall. The landings with 2 or 3 sides supported, the steps cantilever and supported by landings.