Click on heights in the Nominal Height column to choose other pages
All heights assume 1-1/2" non-shrink grout below the column.
H1 assumes a single 2x6 on top of the pre-installed beam nailers.
All widths assume single 2x6 nailer on each column flange
Naming Scheme:
- Allowable shear loads assume a pinned base and are applicable to seismic designs utilizing R = 3.5 and wind designs. For seismic designs with R=6.5, multiply design loads by 6.5/3.5.
- Maximum Shear is allowable horizontal shear force, V, applied in combination with the following allowable stress design uniform gravity loads: w = 800-plf dead load, 400-plf floor live load, and 400-plf roof live load. Seismic load combinations assume SDS=1.0 to determine Ev. Where SDS>1.0, check that (1.0 + 0.14SDS)D is less than 800 plf. Where gravity loads exceed any of these values, use Minimum Shear loads (see Note 3).
- Minimum Shear is allowable horizontal shear force, V, applied in combination with the maximum total vertical load, Wmax, which may be applied as a single point load at midspan, P=Wmax, as multiple point loads applied symmetrically about mid-span of the beam,P1+P2+…+Pi=Wmax, or as a uniform distributed load, wMax = Wmax/Lbeam.
Wmax shall be determined based on the governing load combination of the applicable building code, and shall include Ev for seismic loads
- Horizontal column shear reactions can be solved by the equations below. Maximum horizontal shear reactions occur at the compression column. Designer to determine governing load combinations based on the applicable building code.
Compression Column:
RH =
+ X(P)
or
RH =
+ X(
wL)
Tension Column
RH =
V = Design Frame Shear (lbs)
P = Midspan Point Load (lbs), based on governing load combination
w = Uniform Load (lbs/ft), based on governing load combination
L = Column Centerline Dimension, W1 + 3" + Column Depth (ft)
X = Frame Shear Reaction Factor (no units)
- Tension reactions are for Maximum Shear with a resisting vertical load equal to (0.6 - 0.14SDS) times the frame weight, based on an assumed SDS=1.0. Where Maximum Shear is not listed, tension reactions consider Minimum Shear. Reduced ASD tension forces may be calculated by the Designer by statics. See Example #2 for calculation of reduced tension with applied lateral shear and resisting vertical loads.
T = (Vh-MR)/L
V = Design frame shear (lbs)
h = Steel column height, H1-6" (ft)
MR = Resisting ASD factored moment due to dead load (ft-lbs)
L = Column centerline dimension, W1 + 3" + column depth (ft)
- Fastening is minimum nailing or Simpson Strong-Tie® SDS screws (SDS) to achieve the full allowable shear load. For seismic designs (SDC C through F, except 1 and 2 family dwellings in SDC C), Designer shall evaluate if top plate to nailer conection is required to be designed for overstrength force levels and increase fastening as required for Em level loading. Top plate splice, as required, by Designer.
- Drift at allowable shear is applicable to both Maximum Shear with uniform load, w, and Minimum Shear with maximum total load, Wmax. Drift may be linearly reduced for shear loads less than allowable shear, and for wind drift checks as suggested by ASCE 7-05 Section CC.1.2. Allowable shear may be linearly reduced for more restrictive drift limits.
- Allowable loads consider LRFD load combinations for uplift of 0.1D + 1.4E and 0.1D + 1.6W.
- Vertical beam deflections due to unfactored ASD gravity load do not exceed the following:
Dead load
Floor live load
Dead load + floor live load
WMAX (Point Load)
- See OMFSL and OMFAB anchorage solutions.
- Allowable stress design uniform gravity loads per footnote 2 must be reduced. See Minimum Shear and footnote 3 for maximum gravity loads.
- Alternate combinations of lateral load and gravity load are possible for some frames. Use alternate loading worksheet or use Strong Frame™ Selector software.
- Where noted in table, reactions applicable to designs based on wind and seismic design using R ≤ 3.0.
- Where noted in table, shear reactions for use in design of column base anchorage in accordance with AISC 341-05, Section 8.5b, for designs with R = 3.5.
- Where noted in table, minimum of the shear calculated for the compression column from ASCE 7-05 load combinations with overstrength factor, and the shear associated with yielding of the frame. Reduced shear may be calculated by the Designer using footnote 4 by substituting Ωo*V for V.
- Drift limit is based on the allowable story drift for ASD seismic loads, and is equal to 0.7 (0.025h/Cd) = h/171, where h = H1 and Cd = 3.0.
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