RC Column
EN 1992-1-1 · rectangular · axial load + biaxial bending, slenderness (5.8.8), interaction diagram
Section and geometry
Design actions (ULS)
Same sign for M01 and M02 = single curvature. Mx acts in the h direction (strong axis).
Materials
Column design passes · 4Ø12 (ρ = 0.28%)
Longitudinal: 4Ø12 = 452 mm² (0.28%)
Links: Ø8 @ 225 mm (× 0.6 near beam/slab joints)
Design moments: MEd,x = 42.2 kNm, MEd,y = 30.0 kNm · utilisation 0.226
3D view
Checks
- OKCapacity (N–M interaction) utilisation 0.226
- OKMinimum reinforcement 452 ≥ 345 mm²
- OKMaximum reinforcement 452 ≤ 6400 mm² (4%)
- OKLink diameter input Ø8 ≥ required Ø6
- OKSlenderness λmax = 23.6 (second-order method suited to λ < ~140)
Calculation
Design actions and slendernessEN 1992-1-1 5.2, 5.8
| NEd | 1500 kN | |
| fcd / fyd | 20.00 / 434.8 MPa | |
| x–x (h dir.): effective length l0 | β L | 2720 mm |
| x–x (h dir.): slenderness λ | l0 / i, i = D/√12 | 23.6 |
| x–x (h dir.): limit λlim | 20 A B C / √n [5.8.3.1] | 31.0 |
| x–x (h dir.): first-order MEd0 | max(0.6 M02 + 0.4 M01, 0.4 M02) + NEd l0/400 | 42.2 kNm |
| x–x (h dir.): second-order | not required (λ ≤ λlim) | |
| x–x (h dir.): design moment | max(M02, M0Ed + M2, NEd e0), e0 = max(D/30, 20) | 42.2 kNm |
| y–y (b dir.): effective length l0 | β L | 2720 mm |
| y–y (b dir.): slenderness λ | l0 / i, i = D/√12 | 23.6 |
| y–y (b dir.): limit λlim | 20 A B C / √n [5.8.3.1] | 18.1 |
| y–y (b dir.): first-order MEd0 | max(0.6 M02 + 0.4 M01, 0.4 M02) + NEd l0/400 | 10.2 kNm |
| y–y (b dir.): second-order M2 | NEd · Kr Kφ (1/r0) l0²/10 [5.8.8] | 18.1 kNm |
| y–y (b dir.): design moment | max(M02, M0Ed + M2, NEd e0), e0 = max(D/30, 20) | 30.0 kNm |
Section resistance (strain compatibility)EN 1992-1-1 6.1, 5.8.9
| Reinforcement | 4Ø12 (nb = 2 per face, nh = 0 per side) = 452 mm² | |
| As,min / As,max | max(0.10 NEd/fyd, 0.002 Ac) / 0.04 Ac | 345 / 6400 mm² |
| NRd (squash) | Ac fcd + As fyd | 3397 kN |
| MRd,x at NEd | 186.9 kNm | |
| MRd,y at NEd | 186.9 kNm | |
| Utilisation | max(MEd/MRd) per axis | 0.226 |
DetailingEN 1992-1-1 9.5
| Link diameter | max(6, φmax/4) | Ø6 (input link Ø8) |
| Link spacing scl,tmax | min(20 φmin, min(b,h), 400) | 225 mm (× 0.6 near beams and laps) |
Scope: rectangular sections, braced or unbraced via β, nominal-curvature second-order method, fck ≤ 50 MPa; bars on the perimeter only. Results are an aid only and must be verified by a qualified, licensed engineer before use. National Annex presets are recommended values and must be checked against the official documents.