Canadian Column Capacity Calculator — CSA S16-19

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Design per CSA S16-19 Clause 13.3

Check the compressive resistance and stability of Canadian steel columns per CSA S16-19. The calculator supports W-shape sections in 300W, 350W, and 380W steel grades.

Supported Sections and Grades

• W-shapes — W100× to W1100× series (Canadian metric sections)
• Steel grades — 300W (300 MPa yield), 350W (most common), 380W
• HSS sections — Square and rectangular hollow structural sections

Design Checks Performed

• Cross-section compressive resistance — Cr = φ × A × Fy per Clause 13.3.1
• Member compressive resistance — Cr = φ × A × Fy × (1 + λ²ⁿ)^(-1/n) per Clause 13.3.1
• Non-dimensional slenderness — λ = (KL/r) × √(Fy/π²E) per Clause 13.3.1
• Combined compression and bending — Clause 13.8.2 interaction for Cr + Mr
• Class limit check — Clause 11 slenderness limits for flange and web in compression

Worked Example

Problem: Check a W250×73 column in 350W steel with a 5.0 m effective length and a factored axial load of 1500 kN.

Solution:

• Section: W250×73, 350W (Fy = 350 MPa)
• Area A = 9280 mm², radius of gyration ry = 64.6 mm
• Cross-section resistance: Cr = 0.9 × 9280 × 350 = 2923 kN
• Non-dimensional slenderness: λ = (5000/64.6) × √(350/π²×200000) = 0.91
• Member resistance (n = 1.34): Cr = 0.9 × 9280 × 350 × (1 + 0.91^(2×1.34))^(-1/1.34) = 1794 kN
• Utilisation: 1500/1794 = 0.84 (84%) — OK but marginal

Result: W250×73 in 350W is adequate with 84% utilisation. Consider upsizing if additional loads expected.

Related Resources

• Canadian Column Design Guide
• Canadian Steel Grades Fy/Fu
• Canadian Column K-Factor Guide
• Canadian Beam Design Guide

FAQ

What is the resistance factor φ for columns in CSA S16? The φ factor for compression members is 0.9 per CSA S16-19 Clause 13.3.1.

How does the calculator handle the slenderness reduction? CSA S16-19 uses the factor (1 + λ²ⁿ)^(-1/n) where n = 1.34 for W-shapes (hot-formed). This is based on the SSRC multiple-column curve approach and is equivalent to the AISC LRFD column curve.

Does CSA S16 use different buckling curves for different sections? Yes. The parameter n varies by section type: n = 1.34 for hot-formed shapes (W, S, C), n = 2.24 for cold-formed HSS, and n = 2.24 for structural tubing per CSA S16-19 Clause 13.3.1.

What about combined compression and bending? Clause 13.8.2 interaction is checked for biaxial bending and axial compression using the interaction formula Cf/Cr + Mfx/Mrx + Mfy/Mry ≤ 1.0.