shear wall unsafe in shear

[chekre]

Hi guys,

when u build a 3D model and after running the model, u notice that one of the many shear walls is unsafe versus shear (the other walls are safe), what i generally do is the following and would like to share my thoughts with you :

1- assign modifiers for f12 (0.7) so the wall could give some of the carried shear to the adjacent walls which the modifiers are unchanged.

2- Model the wall as a column so it wont get the transfered shear and will be distributed to the adjacent elements.

your thoughts are appreciated.

thank u

 

[briancpotter]

You can't simply change your modeling parameters if you don't like the results it's giving you. Deciding to call it a column won't change how much load transfers into the real, physical building.

You have a few options:

1) If you change it to a column, you have to also change your construction details to ensure load can't transfer into it. How you do this depends on construction type (using sliding connections, etc.).

2) Strengthen the wall, by adding reinforcing/section/etc. until it can handle the loads.

3) Shrink the wall/enlarge the other wall so the shear distribution is more to your liking.

It's hard to know which (if any) of these is necessary without knowing more about your modeling program, construction type, etc.

Brian C Potter, PE

http://simplesupports.wordpress.com

 

[XR250]

I do not see a problem doing what Chekre suggested. If the wall is potentially going to fail anyway and the other elements are designed for the additional load (as they would be if it is modeled as a column), what is the issue? Seems like just more redundancy to me. Let's face it, we can model this stuff all we want, but the way it actually behaves in the real world is likely to be different.

 

[hokie66]

Agree with Excel. Try to think like the structure, rather than forcing it to do what you want it to do. Overstress of one building element need not be considered failure.

 

[chekre]

Thanks guys.