Shear Walls In ETABS 3

[ADCanada]

Hi To All
I am fairly new in ETABS and I have now a situation where not all the walls are to be used to resist the lateral seismic forces. Or on other words I have existing walls and I want to introduce to a structure new shear walls that should take the seismic forces up to a certain floor level.

The issue here is which is more correct:
1. Give the non-seismic walls a very low stiffness Modifier of lets say 0.001 for f11 and f12 in order to have these walls accept axial loads only.
or....
2. Shall i replace these walls with columns and have their frame release in shear moment and torsion and keep Axial load.

Your opinion is highly appreciated...

 

[slickdeals]

If you can get away with not modeling the wall, that's a better way than to mess around with the stiffness modifiers on it.
Or model the wall to 6" below the slab, draw a couple (or as many needed) dummy columns to support the slab, and model the column with pinned ends. That way the wall will pick up axial but no moment.

 

[ADCanada]

@slickdeals
Thank you, it did work, and i also made the effort by deleting the walls that we do not need and adding columns instead and have them with pinned ends as you suggested. As for the deleted walls i added their self weight into the slabs.

Now I am trying to find if there is any UPLIFT at the ends of the shear walls, and i did the following...
1. Selected the points at the base that correspond to the ends of the Shear Walls and then got the results from Display/..Reactions/Support Reactions...
2. All load combinations selected are the DWAL#

But here i found out that all "FZ" are in positive,I hope here that the results are right. Or is my method wrong?

 

[johnbridge231]

I think your approach is ok

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html