AISC 360-22 §J8 & Design Guide 1 | Steel Column Base Plates
Steel columns concentrate immense axial forces over a small steel cross-section that would crush supporting concrete foundations directly. A steel base plate spreads the column load over a larger bearing footprint while resisting upward cantilever bending around the column flanges and web.
Governing Formula
Check Automatically
AXIS verifies AISC 360-22 / DG 1 limits directly inside your models with full step-by-step math.
Notation & Variables
Worked Example
Verify concrete bearing capacity
Check that factored axial load Pu ≤ φc Pp (where confinement factor sqrt(A2/A1) is capped at 2.0).
Compute cantilever extensions m and n
Calculate plate projections m = (N - 0.95d)/2 and n = (B - 0.80bf)/2 beyond the critical bend lines.
Size plate thickness tp
Evaluate t_min using the governing cantilever l and select the next standard plate thickness.
When does this govern?
Governs every steel column-to-foundation interface in structural steel buildings and industrial structures.
Common Mistake
Using 0.95d and 0.80bf critical bend lines for HSS tube columns; HSS columns use 0.95 times both outside tube dimensions.