In a wood shearwall, the bottom plate is nailed to the rim joist or board below through floor sheathing.
Based on IBC 2006/NDS 2005 I'm getting the following allowable value, which is substantially higher than what we had used in prior code cycles.
1 ½" thick (2x Plate) Douglas Fir-Larch G = 0.5
16d Common Wire Nails L = 3 ½", D = 0.162"
Maximum Floor Sheathing Thickness t = ¾"
Load Duration Factor CD = 1.6 (Wind/Seismic)
Reference Lateral Design Value Z = 141 lb (NDS-2005, Table 11N)
Based on full 10D or 1.62" Penetration
Minimum Required Penetration pmin = 6D = 0.972"
Actual Penetration p = 3.5"-1.5"-0.75" = 1.25" > pmin OK
Adjust for Reduced Penetration 1.25/1.62 = 0.7716
Allowable Shear per 16d Nail Z' = 0.7716 x 1.6 x 141 = 174 lb
Does this look reasonable or did I miss something?
Your Input is greatly appreciated.
Peter