Proposals to design a 50m cantilever transfer slab 1

[Sujitha Menon]

Good day
This is for a project in Dubai where in I have a 50m cantilver edge at the corner of the building starting from 2nd floor and the building projects out to carry 10 floors of hospital above . what will be the best proposal to design this area.The General internal floor slabs are flat slab with column drops.As cantilver support columns are spaced at 10m apart can I propose a deep 50m cantilver steel truss at every 10m span .with a back span for the span.How do I curb the huge moments incurred in the supports.Is there any option other than steel.Great if you can send me any reports you have in hand .Yes it is a 50m cantilver transfer slab--

 

[jayrod12]

We're going to need some sketches. Your framing arrangement is extremely hard to follow with only a worded description.

A plan view showing column locations and a section view would probably allow some of the extremely bright people here give you some real insight.

To start, a 50m cantilever seems extreme. Are you sure about your units and terminology?

 

[Tomfh]

50m cantilever transfer! Wow

 

[Sujitha Menon]

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1605760632/tips/Hospital_Dubai_ldzxbc.pdf[/url]

 

[Tomfh]

The scale seems all wrong. The “50m” dimension is nowhere near 5 times the “10m” dimension.

 

[Sujitha Menon]

The Sketch attached is arbitrary and not to scale. Just a diagrammatic representation of the proposal requested

 

[Tomfh]

Ok. Well good luck with it.

 

[human909]

The words "50m & cantilever & slab" are not words you expect to find together. Hence the continue disbelief express.

If you do want a cantilever without dropping a column to ground then then you likely want to engage many floors above to allow the slabs form a deep beam that is numerous stories high.

 

[Sujitha Menon]

there are projects which I found for 66m but with 2 to 3 floors above with vierendeel trusses of 3 floor height.

 

[dik]

I suspect that you have to use the outside walls and cantilever it the 7m distance from the interior columns to the outside wall. It's a huge cantilever and I don't know if it can be done... but, maybe a solution similar to what I've proposed.

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

-Dik

 

[Agent666]

what will be the best proposal to design this area

How do I curb the huge moments incurred in the supports

Put a column or two in starts to solve all your issues.....

50m cantilever sounds pretty ridiculous to support a high importance structure like a hospital. I'm curious what are the proportions of the cantilevering truss, how deep, how much back-span, & how much does it deflect.

Concrete might work. Several storeys deep cantilevered beam?

 

[Trenno]

Perhaps you could walk down the road and observe this cantilever.

 

[HTURKAK]

Sujitha Menon, will you please post a scaled sketch showing the full plan with columns and perimeter of slab? I could not visualize the plan..

 

[MIStructE_IRE]

You’re not going to get a response on how to design the world’s craziest building from us strangers on the internet.

Hospital floor vibrations are usually critical for their very sensitive machinery. I think the client needs to reconsider building a 10 storey hospital over 50m of fresh air...

Putting my crazy hat on, if I were to do it, I’d be looking at at least 10m deep trusses (3 storey heights minimum) as a starting point. You have all sorts of vibration, seismic and redundancy issues to consider though. This just doesn’t seem realistic to me.

 

[jayrod12]

I agree with the others, I don't think this is reasonable. especially with only 20m of backspan. The uplift forces on that back end will be enormous. How are you planning on dealing with that?

 

[KootK]

Fun. I've read of theoretical proposals recently to reboot the practice of using high-rise exterior cladding for load bearing and lateral resistance. Basically, undoing the curtain wall concept. Your thing might be accomplished in such a way. It's essentially another version of the multi-story, vierendeel truss concept that you mentioned. Ductility might be a challenge if you're in a high seismic environment. Based on the 7m dimension shown in your sketch, I suspect that this isn't quite as bad as the 50m makes it sound when drawn to scale.

 

[Trenno]

432 Park Avenue on it's side???

 

[KootK]

Yeah, minus the gargantuan strongbox in the middle and done as cladding rather that CIP. Not that CIP wouldn't be an option if were economically feasible.

 

[KootK]

In a similar vein, I suppose that diagrid ought to be considered.

Hospital programming tends to not like interior walls so options with that might be limited.

 

[dik]

Easy... rock anchors...

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

-Dik