Long Column Design Calculator — SP-16 lookup + Buckling checks

Long Column Design — Buckling (Euler)

Upload SP-16 CSV for exact K1/K2 lookup. Compute Euler buckling for several end restraints.

Column width b (mm)

Column depth D (mm)

Floor-to-floor H (mm)

Unsupported length L (mm)

Effective length factor k

Cover d' (mm)

Axial load Pu (kN)

Steel % Pt (0→use default 3%)

Mux (kN·m)

Muy (kN·m)

f_ck (MPa)

f_y (MPa)

Upload SP-16 CSV (optional)

Buckling options

Choose end restraint for Euler check Pinned-Pinned (k = 1.0) Fixed-Free (cantilever) (k = 2.0) Fixed-Pinned (k ≈ 0.7) Fixed-Fixed (k = 0.5)

E = 5000√f_ck (MPa) used for concrete modulus; I = bD³/12 (mm⁴)

SP-16 CSV format notes

• CSV should have columns: d_ratio, pt_over_fck, K1, K2 (case-insensitive) — or close variants.
• If your data is arranged with d'/D rows and Pt/fck columns, export to a 4-column table first.
• When uploaded the script will interpolate K1/K2 for the requested d'/D and Pt/fck.

Results

Click Compute to see full step-by-step results including buckling checks and SP-16 K1/K2 lookup.

Reinforcement sketch

Notes

• All calculations are performed client-side. PDF export uses html2pdf (html2canvas).
• If the SP-16 CSV is not recognized, the tool uses internal approximations similar to the worked example.