310UC80 AS/NZS 3679.1 Grade 300 — Australian Universal Column Section Properties

310UC80 is an Australian UC (Universal Column) per AS/NZS 3679.1 hot-rolled structural steel section. Standard Australian UC dimensions. Verify against Liberty OneSteel / InfraBuild section catalog.

Dimensions (Metric)

Property Value Unit
Depth (d) 310 mm
Flange Width (bf) 310 mm
Flange Thickness (tf) 8.5 mm
Web Thickness (tw) 5.5 mm
Cross-Sectional Area (A) 68.8 cm²
Mass 80.0 kg/m

Elastic Section Properties (Metric)

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 13,132 4,221 cm⁴
Elastic Section Modulus (S) 847 272 cm³
Plastic Section Modulus (Z) 912 411 cm³
Radius of Gyration (r) 13.81 7.83 cm

Torsional Properties

Property Value Unit
Torsional Constant (J) 14 cm⁴
Distance Between Flange Centroids (ho) 30.15 cm

Section Profile Summary

This is a standard hot-rolled I-section profile covered by AS 4100. The tabulated section properties are computed from the nominal dimensions per the governing material standard. With Ix = 13,132 cm⁴, the strong-axis flexural stiffness is suitable for preliminary sizing of beams and beam-columns.

At 310 mm deep, this section is common for floor beams, portal frame rafters, and columns in commercial and industrial buildings.

Key Design Checks (AS 4100)

Check Formula This Section
Plastic moment Mp = Zx × Fy 274 kN·m
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 13,132 cm⁴
Torsion St. Venant = GJ/L J = 14 cm⁴
Column buckling KL/r → Fcr r_x = 13.81 cm

Design Notes

Verification (AS 4100): All designs using this section must be verified by a licensed Professional Engineer. Before finalizing member selection, check beam-column interaction (P-M), lateral-torsional buckling, serviceability deflections, and all connection limit states. See Engineering Disclaimer.

Worked Example: Retail floor beam — 310uc80

Scenario: Retail space — higher live load for public occupancy per EN 1991-1-1. Simply supported I-section, 8.1 m span, 2.4 m tributary width. Service loads: 4.5 kPa dead + 5.0 kPa live (22.8 kN/m total).

Given:

Step 1 — Live load deflection:

Δ_LL = 5 w_L L⁴ / (384 E Ix)

Δ_LL = 5 × 12.0 × (8060)⁴ / (384 × 200000 × 131,320,000)

Δ_LL = 25.1 mm

Step 2 — Deflection limit (L/300):

Δ_limit = L / 300 = 8060 / 300 = 26.9 mm

Step 3 — Dead + live deflection:

Δ_total = 47.7 mm

Step 4 — Design check:

✓ Live load deflection is within the L/300 limit.

Verify the design moment M*_Ed (from factored loads 1.35G + 1.5Q per AS 4100) does not exceed φMn = 246 kN·m. Also confirm shear resistance and bearing details at the supports.

Related Resources

Design Resources


Educational reference only. Verify all section properties against the current AS 4100 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.