minimum footing requirements for shear wall? 1

[EngineerofSteel]

I did calcs for a long building which required existing hallways to be upgraded to 1-hour fire resistance.

Since these walls were being re-paneled anyway, I used the shear resistance to qualify the resisting capacity of the building.

The walls sit on a 4" slab.

The entire slab is surrounded by a 12" below grade perimeter footing. So, I can qualify the bearing beneath the slab as 1500 PSF, and the walls have only 100 PLF.

Does anyone foresee problems at review? It was submitted today.

 

[msquared48]

The only problem I can see is with the required 3" clearance from the soil to any reinforcing steel, to include thge anchor bolts. Normally I thickebn the slab under ther shear wall to 8 to 12" to accommodate this.

I assume with a long wall that holddowns were not needed and that if seismic governed for the gyp that you used half sgtresses for the shearwall capacity?

Mike McCann
MMC Engineering

 

[kslee1000]

what the shear resistance has to do with fire resistance? where is the shear resistance came from, by reinforcing dowels? Sorry, I don't understand your question.

 

[EngineerofSteel]

msquared,

That is a good mention. I thought of it in process, then forgot it.

Using IBC 2006 Table 1911.2, I can spec .25" dia. bolts @ 4' o.c. (500# shear allow). The embed is only 2.5", leaving 1.5" clear.

Plus there is a vapor barrier.

 

[EngineerofSteel]

In the end, I changed my shear distribution almost entirely to proposed wall sections. Where I had to distribute to existing walls, I spec'd powder driven nails at 6" o.c.