WALL DESIGN - OUT OF PLATE SHEAR

[engrnmc]

hi just like to inquire some insight pertaining to wall out of plane shear.

Based on ACI 318-08, out of plane shear shall be design same as slab and footing ( ACI318-08 11.9.1) where Vc is calculated based on the perimeter of it's critical section for shear, using STAAD plate analysis I would be able to get the SQY and SQX. SRSS the two, will give me the ultimate shear (Vu).
My question is, what perimeter should i be using? would it be the dimension of the plate?

 

[KootK]

It would be the dimension of the plate. In this case it's the cross section of the wall. Of course, if you're going to consider the entire wall in one go, you'll need to ensure that the peak shear stress is not significantly more than the average. I'm not sure about the SSRS business. Typically the orthogonal transverse shear components are evaluated independently.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[engrnmc]

sorry just like to clear something,
" In this case it's the cross section of the wall", do you mean, the wall peripheral punching area? would it be the perimeter of the plate times "d"?

about the SRSS thing, it is as Vu = sqrt [ (SQY*length)^2 + (SQX*width)^2 ] * d,
correct me if im wrong, but my understanding of the ACI in calculating the out of plane shear of wall is as a punching shear, Vc = 0.17 sqrt (F'c) bo d (ACI 318-08 11.11.3.1)

if the orthogonal transverse shear components will be analysed independently, would it like a beam shear? where in the section involve is the unit length of SQX times d? is that what you meant about the " cross section of the wall " ? , if so that is what i usually do, but i got confused because ACI is telling me to consider out of plane as a shear at slab and footing.

hope you could enlighten me, thanks

 

[KootK]

I was thinking that this was a one way shear situation rather than a punching shear thing. It seems that I do not understand your situation.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[engrnmc]

that is what we do, its just that i come across with ACI318-08 wall provisions, pointing out (ACI318-11.9.1 : " Design for shear forces perpendicular to face of wall shall be in accordance w/ provisions for slabs in 11.11. . .") going to that said section, Vc is calculated base on sections : 11.11.2.1 ; 11.11.2.2 and 11.11.3.1, where shear is check at its punching shear or withing its critical shear section.

thats is why i come about the punching calculation. my interpretation might not be correct that is why im seeking for further opinion and practices.

 

[KootK]

Do you have a highly concentrated load that would warrant a punching shear check? If not, one way shear seems like the way to go.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[engrnmc]

Well non. Just thinking of using a punching consideration because of the ACI code that i read. Thats why i want others to give their insight of the section.

Non the less thanksthank you. Well considering one way shear and checking SQY and SQX independently is a more conservative approach than what im thinking of. Haha