export internal forces from C shape shear wall

[luungoclinh]

Hi all,
Could someone please tell me what people normally do to export internal forces from monolithic RC C shape shear walls using Etabs that will be used for sectional analysis? Will you define 3 piers for C shape (web + 2 flanges) or only one pier? If there is only one pier, how do you consider torsion in design (shear...)?
Thanks
Lisu

 

[johnbridge231]

As you will perform a sectional analysis, you will need to export the internal forces of the entire wall shape, so a common pier label for all wall elements belonging to that should be the best choice.
Torsion can be ignored if the wall is not closed. Shear chhecks as per design code. I could recommend you this tool, which performs sectional calculation of your interest.

Regards.

 

[PicoStruc]

«Torsion can be ignored if the wall is not closed»

you need a model with a global pier to extract blending,

You need a model with 3 local pier to extract local shear -> Torsion induce shear in the flanges that cancel each other in the global shear response. But it is there locally !

 

[luungoclinh]

Thanks you for your responses. I have another question abt reinforced concrete C shape shear wall design> I hope that you can help me to clarify it.
When I follow capacity design for a C shape shear wall, I need to design shear corresponding to the expected development of flexure at the base. It means that shear force design obtain from linear analysis of Etabs will be amplified by overstrength factor of the wall at the base. However for C shape, I dont know how to define overstrength factor. Because we should have totally 4 combination of sectional analysis(Mx+My; minus Mx+minus My;Mx+minus My;minus Mx+My) with 4 overstrength factors.
Thanks
Lisu