] [Thread] [Date] [Author]

[Sam Chang <szchang(--nospam--at)mail.arc.nasa.gov>]

UBC no longer carry table for "Holding Power of Bolts." I did
some calculations on the seismic shear capacity for the old 2x and the
new 3x mud sills following 91 NDS.  

I got:

748 pounds for 1/2" dia. anchor in an existing
2x RWD sill,
1077 pounds for drilling in a new 5/8" dia. anchor in an existing
2x RWD sill &
1488 pounds for 5/8" dia. anchor in a new 3x pressure treaded
DF #1.

I would like to find out what values are you using?

Sam Chang, SE


At 06:03 PM 4/7/00 -0700, you wrote:
>
>
>The requirement of 3x applies to new construction. However, you can
utilize an
>existing 2x for wall anchorage. The loads should be concentric on the
(E)
>framing and adequate nailing to the plywood panel is necessary to
develop the
>O/P wall loads into the subdiaphragm sheathing. The purpose of using
3x is to
>achieve proper nailing pattern at the plywood panels edges without
splitting 
>the
>framing member and maintaining enough effective area of the framing
member 
>after
>loss of section due to drilling. An alternative to drilling the (E)
2x is to 
>use
>self drilling screws.
>