Special Reinforced Masonry Shear Wall

[knelli]

Hi,

If you have a building in Seismic Design Category D, Special Reinforced Masonry Shear walls are required. Per ACI 530, "1.13.2.2.5 c)Shear reinforcement shall be anchored around vertical reinforcing with a standard hook."

This makes me think that horizontal reinforcing needs to be via bond beam with rebar and not joint reinforcement. What do you think? Does every bar need to have a hook around the vertical reinforcing? So if you have vertical reinforcing at 48" o.c. and your horizontal bars are #4 in a bond beam at 48" o.c. then every horizontal bar will be about 4' long with a hook at each end? Or can they be about 8' long with a hook at each end?

Is there a resource for special seismic detailing? I have the 2006 IBC Seismic Design Manuals. I did take a look at TEK 14-18A Prescriptive Seismic Reinforcing Requirements for Masonry Structures.

Are there any requirements for the maximum spacing of shear walls with a flexible diaphragm?

I have no experience designing in SDC D and am quite nervous. We do not have the project yet.... Thank you in advance for your advice.

-K

 

[Lion06]

I don't think the intent was to hook around each vertical bar.
Also, bond beams would be the conventional way to provide the horizontal shear reinforcement, but there are Ivany blocks available that have notches in them to allow for placement of horizontal steel. The only problem is you have to grout it solid.

 

[sandman21]

If you are required to have shear reinforcement that is the masonry can't take the shear alone, the horizontal reinforcement must end with a standard hook around the vertical rebar at the ends of the shear wall. My ACI 530 is at work there are limitations on rebar spacing regards of diaphragm type.