reduced result in walls

[saclovitzky]

Hello,

I've met a very strict consulting engineer(ARUP) who are not familiar with "ins and outs" of ARSAP.

He questioned me regarding the output of "reduced result" for panel.

Normally, I usually used "reduced result" for panels in designing rc walls.

Then, he questioned one particular panel with "uplift force" on one edge,then,looked at the result("reduced result").

He said that how is ARSAP take into consideration the uplift force,in terms of providing reinforcement.

Also, he commented, that portion of a wall with uplift should be treated differently.

As I have told him, that ARSAP "internally" take into consideration the "uplift force" in providing result for the "reduced result" in that particular panel(he doesnt see convinced!).

Any help with additional explanation to convince him will be greatly appreciated(pls. see attached screenshot for my complete queries)

[saclovitzky]

any comment Rafacascudo?

[Rafacascudo]

Can you zip and send the model?

[saclovitzky]

Pls. see attached

[Rafacascudo]

@saclovitzky 

  Hard to analyse this "panel only" structure using reduced results ,as if the wall in question was a beam. Worse trying to do it through the Reduced results table . I would use limited panel cuts to check the forces that are acting and use them to design the reinforcement.

For example in the region of uplift you can use the resultant tension force on that region of the wall.

With that result type you can design it by yourself or ,at least check if RSA is doing it right.

I do not use the Concrete module, as it does not support the Brazilian codes.

Reduced results from Graphic Panel cuts are very useful if used as described above

[Simau]

Hi @saclovitzky 

In jour model, change structure object to « wall »

In <job preferences> as provided reinforcement for wall is not implemented BS code in Robot, change it to French code "BAEL.

In these sceenshots below Look at values equivalences

Provided Wall reinforcement takes into account tension and compression in the wall

A small example  and you updated model are attached

[Simau]

sorry duplicate

[Simau]

Message 6 updated:

You said:

He said that how is ARSAP take into consideration the uplift force,in terms of providing reinforcement.

Provided reinforcement is calculated taking into account tesion and compression as yo can see in Reinforcement parameters applied to the walls.

[DonBAE]

This is really a question as to whether traditional wall design applies in your case or if thin shell provisions are applicable.

In your specific case I would lean toward thin shell provisions per ACI 318.2. This would require concentrated steel in your tensile stress zone.

In the traditional wall design you check against a P-M curve using the reduced results with “long” wall panels the reduced results aren’t really fully describing the stress state in the wall panels. Understand that reduced results are really just integrating the force and moment about the wall panel centroid if you were to decompose the resulting axial force and moment using the standard P/A +/- M/S formula you won’t end up with the same concentrated tension instead it will be smoothed out considerably.

Unfortunately the design of long walls like this is not clearly defined in the code and it becomes engineering judgment on when to use thin shell vs wall P-M.