SLENDER Concrete Shear Wall analysis

[seattlemike]

Hi All,

So, typically, I've seen engineers run ETABS linear(elastic) dynamic analysis of Concrete Shear Walls, with ACI effective stiffnesses for cracked and uncracked sections.

On smaller buildings, I've seen engineers just run RISA wall panels elements, discretized to get tensile forces for rebar.

But does anyone have other methods they would recommend?
Anyone attempt to use SAP?

But even with SAP, that program does not capture SLENDER wall buckling? Any thoughts? I know the code had a Lu/16 requirement at one point, but there are plenty of 30 ft warehouse walls that use 6" concrete panels?

What's the good word on SLENDER walls? (for in-plane forces)

Thanks,
SeattleMike

 

[ash060]

For slenderness in walls you really only have to worry about the weak axis as far as moment magnifaction. The inplane forces such as the shear due to lateral loads will not have to be adjusted.

Also the moments in the wall out of plane are going to be very small, but you can design the wall using the provisions in chapter 10 of the ACI code. Just use the moment magnifyers in code.

I do not think that ETABS does this it only designs for in-plane moments and Axial forces.