UNREIFORCED BEARING BRICK WALLS

[mlevario99]

I have a project, where an existing single-story building from the 50's will be converted into a police station. From the international existing building code if you change the occupancy of the building into a higher-risk category then the structure shall conform to the seismic requirements for a new structure of the higher-risk category. For the lateral system I will need to introduce new shear walls, or steel frames. my question is more about the gravity system, and the bracing of the brick walls. The interior corridor is load-bearing unreinforced brick walls ( 2 wythe, I believe), can those be left alone, or do they need to be analyzed and the properties of the existing brick tested to obtain the design values of the brick?

There are some exterior brick walls, do the walls need to be braced to a new interior metal stud wall?

 

[Aesur]

I believe those would need to be analyzed, but am not 100% positive as I only dig into the IEBC when needed. If they are double wythe, what's to keep you from dropping some rebar and grout between and making reinforced if they don't calc out as un-reinforced?

 

[milkshakelake]

I haven't done an upgrade in occupancy/risk category but I've done vertical or horizontal expansions, which is similar because it adds loading. I always put in new shear walls or lateral bracing.

Since your question is about gravity, if those walls are not being used in the lateral system, I don't see why you need to worry about upgrading them. You'd only need to do that if you're increasing the loading on them. But even if you are increasing the loading, you can use minimum recommended brick design values from ASCE 41-17, and it might still work.