Shear Wall Analysis & Design 2

[Redtelis]

Hi,

I guess my question has been made already in past but I couldn't find it by checking the last pages.

Could you please recommend any good worked example / book for shear wall analysis and design? I am working on a 20storey rc frame on ETABS and I want to verify the ETABS results by doing hand calcs.

Many thanks in advance.

 

[Trenno]

In your ETABS model assign pier labels to the individual wall panels. You'll then be able to get the pier forces (ie the axial, bending and shear within each wall panel).

You can then simply do a P/A +/- M/Z check to see how high the stresses are at the ends of the wall. Conservatively you can take the maximum tension stress (if there is any?) and assume it applies over the last 1m of the wall. Using this force, you can then back calculated the equivalent area of steel required.

Similar situation for the compression end of the wall. Think of it as a mini 1m long column. What is the stress and what is that stress as a function of the concrete grade? Is it over 0.4f'c?

Also remember for shear wall design it's not correct to envelope results. You need to co-existent forces to do the P/A +/- M/Z check correctly.

 

[Redtelis]

Many thanks for your reply. I think I got in my mind the main approach on how to cross check the ETABS results with some hand calcs and I agree with your approach to check conservatively the max.stresses.
On the other hand I am struggling to do that on paper as I have never done it before and none in the office has time to go through this. Is there any worked example available on internet for a c shape core wall arrangement?

 

[Trenno]

It's a bit concerning nobody in the office has time to help you design something you're not quite sure about. A 20 storey building's lateral system is nothing to sneeze at.

What code are you designing to? One approach could be to open the ETABS manual for that code. Help > Documentation > Shear Wall Design. That way you'll be able to follow along with what ETABS is doing in the background.

For a 20st building, I would have thought you'd have maybe 2 lifts and a set of stairs. This would mean you'd probably have a bit more than a C shaped core arrangement? Is the C shape really a rectangle with openings on one side? If so, that means you will have link beams going across the top of the opening and below the slab above. This is a whole other topic, but one you will need to brush up on too.

 

[Guest262653]

In a recent thread I've recommended the following books for load path analysis and building stability:

- Stability of buildings (IStructE guides), parts 1, 2, 3 and 4
Parts 1 and 2: General philosophy and framed bracing
Part3: Shear walls
Part 4: Moment frames
- Concrete Buildings Scheme Design Manual, Concrete Centre
- Tall Building Structures - Analysis and Design, Smith
- Structural Analysis of Regular Multi-Storey Buildings, Zalka
- Global Structural Analysis of Buildings, Zalka