ASD/LRFD Manual - American Wood Council

10 M3: Design Provisions and Equations
M3.10 Design for Bearing
Columns often transfer large forces within a structural
system. While satisfaction of column strength criteria is
usually the primary concern, the designer should also
check force transfer at the column bearing.
For cases in which the column is bearing on another
wood member, especially if bearing is perpendicular to
grain, this calculation will often control the design.
The basic equation for bearing design is:
R′ ≥ R (M3.10-1)
where:
R′ = adjusted compression perpendicular
to grain capacity, lbs
R = compressive force or reaction, lbs
The equation for calculation of adjusted compression
perpendicular to grain capacity is:
R′ = F c ′ A (M3.10-2)
where:
A = area, in. 2
F c ′ = adjusted compression perpendicular
to grain design value, psi. See product
chapters for applicable adjustment
factors.
American Wood Council