Workaround for a Stair to join Slab in a correct way.

[florin.florescuKPSEU]

Hello Everyone!

Please offer some advice on a problem I repeatedly tried to solve and could not come to any result.

I am trying to build a concrete stair for an architecture project. The stair needs to be joined to the upper and lower slab in a certain way which can differ from project to project, depending on the structural solution.

In image 3 we have the structural drawing for the stair I am about to build.

In image 1 we have the actual situation and my question is the following: is there any solution for me to make a connection between the stair and the slab so that they match the structural project in image 3?

My previous approaches were to cut the slab (or the screed - like in image 2) with triangular voids and add a triangular model in place, with the same concrete material.

Still it must not be like this because I am not sure how will a structural engineer can reinforce that stair using what I give him.

Surely there is another way, much simpler and more effective and hope you can help me with it.

Thank you,

Arch. Florin Florescu

[barthbradley]

My read on it is that you have a precast monolithic flight with landings, but you are modeling it without landings.  Instead, you are modeling it floor to floor.  No landing needed in the precast.  Maybe the correct precast would be one without landings? 

FWIW:

 

[Anonymous]

Something like this?  

[florin.florescuKPSEU]

Thank you for the suggestion.

The solution was given  to us by structural engineers. It seemed correct for we already have the rebar scheme for it and it's connected with both the upper and lower concrete slab.

This is the solution:

We have a concrete slab and a 15 cm  layer above the concrete slab containing finishing, reinforced screed and thermal insulation. I have to connect the stair to this slab and this is what I get:

1. In the image, the stair is made without checking "begin with riser" and with "Extend below tread base" at a negative value. Looks good but I cannot join the slab with the stair even though there are the same materials used.

And in the floor plan, I get the intersection line which looks like a step and it's not ok.

This is how the section looks.

I was searching for a way to make it work for this shape.

[florin.florescuKPSEU]

This solution works well regarding the intersection between the slab and the landing.

However, I get that line in the floor plan that can be interpreted as an additional stair.

I need to be able to solve it with a stair with two runs and one landing between them, created between two levels. I can add an extra landing for the second level but I'm having difficulties to have one landing at the start along with the other two.

It also does not suit for multistorey stairs.

[barthbradley]

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@florin.florescuKPSEU wrote:

Looks good but I cannot join the slab with the stair even though there are the same materials used.

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That was what I was talking about. You can't join them and make then into a monolithic. And, based on your description, they're not going to be joined (monolithic) in the field either. Cold joined maybe, but I doubt that. Either way, not showing them joined in CDs would be the accurate representation.  

[florin.florescuKPSEU]

I must have misunderstood.

I only need accurate architecture representation. Floor plans, clean section and good 3d view and was wondering if I can achieve it without adding filled regions or other tricks.

[barthbradley · Accepted solution]

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@florin.florescuKPSEU wrote:

I must have misunderstood.

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Maybe I misunderstood. 

But yeah, if you just want to eliminate linework in the view, you could also use the Linework tool to make lines invisible.  

[florin.florescuKPSEU]

Thank you very much!

I'll find a way to intersect it correctly and also use the linework tool.