Vertical Shear Reinforcement in Shear Walls

[pfaa]

Hi

I am wondering whether we have to add vertical shear reinforcement calculated as per Cl 11.9.9.4, Eq 11-30 ACI 318-08
with the reinforcement calculated for vertical load and in-plane Bending Moment.

In my case, for low shear wall with high shear force, as per Eq 11.30 vertical shear reinforcement requirement is 0.75%
and for vertical load and in-plane moment as per PCA Column output I need 0.35% reinforcement.

In this case, should I provide total vertical reinforcement as 1.05% or maximum of shear and axial load demand i.e. 0.75%

Please suggest

Regards

 

[DST148]

Provide maximum of [Shear Demand or (Axial + Bending demand)]. You don't have to add the two.

 

[pfaa]

Thanks DST148 for the reply.

I request you to elaborate on the concept of providing maximum of [Shear Demand or (Axial + Bending demand)].

Please suggest a suitable reference for this criteria.

Thank you very much for your help

 

[johnbridge231]

You can design the shear wall using a software (or spreadsheet) for arbitrary cross sections.
As for the shear reinforcement, you can calculate it easily by assuming that the forces is entirely carried by the links.

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

 

[wannabeSE]

Some would be a little more conservative than DST178 and use 100%(0.0075) + 30%(0.0035) = 0.0086 (0.86%). For seismic loading, I would use ASCE 7, Direction of Loading in section 12.5, as a guide.