Concrete slender wall design 4

[0404]

I have designed a load bearing concrete wall for one-storey building, Wall thickness t=59mm, height h=3000 mm and one single layer #4 bars @ 250mm vertically reinforced at center of the wall. The h/t =50.8 and kL/r =135.6 of the wall shows a very slender wall. I figured out the P-M diagram for the wall. I tryed to use the magnified moment method specified by ACI318 Cl 10.11 – 10.12. It was very hard for me to guess the EI in order to calculate Pc. Any ideas on how to get this? Thank you.

 

[amokhta]

In the same section of ACI318 two alternative formulas are suggested to compute EI. So you do not have to guess EI. Just be careful that Beta-d is defined differently for non-sway and sway frames. Read the commentary.

 

[dlew]

0404

Did you say the wall is 59mm thick?
That's only 2-5/16" thick!

I don't believe ACI 318 covers that thin shell element

AEF

 

[0404]

dlew, thanks for the reply. Yes, the wall is 59mm thick. I am also not very sure how to engineer the 59mm thick wall (2-5/16" thick). But it seems to me it is not ruled out to design 59mm walls using ACI10.2, 10.3 10.10. My point is 59mm concrete wall (3000mm high) still has some capacity for moment and compression. Any ideas on how to design it?

 

[ishvaaag]

Tilt-Up walls go up to 50 and above slenderness. I have some pdf dealing with this, but basically must conform to the PCI procedures for such walls. If I find the pdf article, will post the reference.

 

[JAE]

I would be very nervous about a 2-5/16" thick wall. Your variation in form alignment would have a very significant effect on your second-order moments which may be beyond what the ACI approximate method assumes.

 

[flamby]

Instead of going for a rcc wall, see if you can afford to use stiffened steel plate. The gaps between stiffeners can later be filled with concrete to give you desired finish and thickness.

 

What is an approximate method to compute embedment depth for soldier pile for tied back wall with multiple layers of anchors? Soldier piles are embeded in rock.

Thanks for any hint.

 

Sorry for posting my question as response to your wall question.
I apologize for the mistake. It is my first time log on this site.