burnaway
Structural
- Sep 18, 2003
- 4
I've started a new job and inherited some really shoddy typical details. I'm sorting them out as I go along, and today's problem is our shear wall schedule.
I am in California, which uses the California version of the '97 UBC. The schedule I have seems to be based on the '94 UBC (3/8" ply with 8d @ 6" = 264 plf). The darn thing has 16 different shear wall combinations called out, and each one of those lists both CDX and Struct I plywood. But to my main question...
Since I'm not sure of the parentage of this schedule, I am going to check the capacities of the other elements listed myself - anchor bolt size and spacing, sill nailing, A35 spacing, etc. The question is, where can I find the capacity of an anchor bolt in a wood sill to a concrete foundation?
I seem to remember from earlier codes that you would use 1/2 the value of a member twice the thickness in double shear. I can't find that in the current code, and the code doesn't have the nice tables it used to.
I look in the '91 NDS and I see this:
"8.2.3-Wood-to-Concrete Connections
When a connection consists of one wood member attached to concrete or masonry (single shear) by bolts embedded in concrete or masonry, the allowable bolt design value, Z', for a single shear wood-to-wood connection shall apply with:
tm=2ts=twice the thickness of wood member
Fem=Fes=dowel bearing strength of wood member
The concrete or masonry shall be of ample strength to support the applied load"
This seems to lead me to the single shear tables.
For a 2x sill with 5/8" anchor bolts, tm=3", ts=1-1/2", the shear capacity for DF-L would be 880 lbs. With a 1.33 increase the capacity would be 1170 lbs.
For a 3x sill with 5/8" anchor bolts, tm=5", ts=2-1/2", (interpolation required here), the shear capacity for DF-L would be 1000 lbs. With a 1.33 increase the capacity would be 1330 lbs.
Am I calculating that correctly?
I am in California, which uses the California version of the '97 UBC. The schedule I have seems to be based on the '94 UBC (3/8" ply with 8d @ 6" = 264 plf). The darn thing has 16 different shear wall combinations called out, and each one of those lists both CDX and Struct I plywood. But to my main question...
Since I'm not sure of the parentage of this schedule, I am going to check the capacities of the other elements listed myself - anchor bolt size and spacing, sill nailing, A35 spacing, etc. The question is, where can I find the capacity of an anchor bolt in a wood sill to a concrete foundation?
I seem to remember from earlier codes that you would use 1/2 the value of a member twice the thickness in double shear. I can't find that in the current code, and the code doesn't have the nice tables it used to.
I look in the '91 NDS and I see this:
"8.2.3-Wood-to-Concrete Connections
When a connection consists of one wood member attached to concrete or masonry (single shear) by bolts embedded in concrete or masonry, the allowable bolt design value, Z', for a single shear wood-to-wood connection shall apply with:
tm=2ts=twice the thickness of wood member
Fem=Fes=dowel bearing strength of wood member
The concrete or masonry shall be of ample strength to support the applied load"
This seems to lead me to the single shear tables.
For a 2x sill with 5/8" anchor bolts, tm=3", ts=1-1/2", the shear capacity for DF-L would be 880 lbs. With a 1.33 increase the capacity would be 1170 lbs.
For a 3x sill with 5/8" anchor bolts, tm=5", ts=2-1/2", (interpolation required here), the shear capacity for DF-L would be 1000 lbs. With a 1.33 increase the capacity would be 1330 lbs.
Am I calculating that correctly?
