16d Common Nail Lateral Design Value

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                                       C_D = 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                         p_min = 6D = 0.972"

Actual Penetration                                            p = 3.5"-1.5"-0.75" = 1.25" > p_min      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