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 | cmÃÂò |
| 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 | cmâÃÂô |
| Elastic Section Modulus (S) | 847 | 272 | cmÃÂó |
| Plastic Section Modulus (Z) | 912 | 411 | cmÃÂó |
| Radius of Gyration (r) | 13.81 | 7.83 | cm |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 14 | cmâÃÂô |
| 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 cmâÃÂô, 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 ÃÂàFy | 274 kNÃÂ÷m |
| Deflection | ÃÂà= 5wLâÃÂô/(384EIx) | Use Ix = 13,132 cmâÃÂô |
| Torsion | St. Venant = GJ/L | J = 14 cmâÃÂô |
| Column buckling | KL/r âÃÂàFcr | r_x = 13.81 cm |
Design Notes
- Compactness: Verify flange and web slenderness against AS 4100 Table B4.1 classification limits for the governing load case (pure compression, pure flexure, or combined).
- Combined loading: For members under simultaneous axial force and bending, use the interaction equations in AS 4100 Section H. The governing equation depends on the ratio of required to available axial strength.
- Connection limit states: Check bolt bearing, tear-out, block shear, and weld strength at all connections. The governing connection limit state often controls the member size selection.
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:
- Span L = 8060 mm (8.1 m)
- Total service load w = 22.8 kN/m
- Live load portion w_L = 12.0 kN/m
- Section 310uc80: Ix = 131.3 ÃÂà10âÃÂö mmâÃÂô, Sx = 847,000 mmÃÂó, Zx = 912,000 mmÃÂó
- Steel: fy = 300 MPa, E = 200,000 MPa
- Design moment resistance: ÃÂÃÂMn = 0.9 ÃÂàZx ÃÂàfy = 246 kNÃÂ÷m
Step 1 — Live load deflection:
ÃÂÃÂ_LL = 5 w_L LâÃÂô / (384 E Ix)
ÃÂÃÂ_LL = 5 ÃÂà12.0 ÃÂà(8060)âÃÂô / (384 ÃÂà200000 ÃÂà131,320,000)
ÃÂÃÂ_LL = 25.1 mm
Step 2 — Deflection limit (L/300):
ÃÂÃÂ_limit = L / 300 = 8060 / 300 = 26.9 mm
Step 3 — Dead + live deflection:
ÃÂÃÂ_total = 47.7 mm
Step 4 — Design check:
âÃÂàLive 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 ÃÂÃÂMn = 246 kNÃÂ÷m. Also confirm shear resistance and bearing details at the supports.
Related Resources
- Steel Beam Capacity Calculator
- Column Capacity Calculator
- Beam Deflection Calculator
- Section Properties Calculator
- Steel Grades Reference
- Section Comparison Tool
Design Resources
- Section Properties Lookup — Compare with similar sections
- Steel Beam Sizes Reference — Standard beam dimensions
Educational reference only. Verify all section properties against the current AS 4100 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.