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NBCC 2020 Load Combination Generator

Enter signed, unfactored loads for one load effect and the tool lists every NBCC 2020 ultimate and serviceability combination that applies, then picks the governing maximum and minimum. Both 1.25D and 0.9D dead-load variants are generated, so uplift and counteracting cases are covered. The governing combinations are shown as substituted equations.

NBCCBy Arun Kishore, P.Eng. Updated

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Code references

  • NBCC 2020 Table 4.1.3.2: ultimate limit states, Cases 1 to 5
  • NBCC 2020 Table 4.1.3.4: serviceability limit states

Inputs and outputs

Inputs and outputs of the Load Combinations tool
InputsSpecified loads D, L, S, W and E, signed (uplift negative)
Lateral earth or hydrostatic H, prestress or permanent P, temperature or shrinkage T
Unit label (display only)
Live-load occupancy: standard, or storage, assembly or parking
Include ULS, SLS or both
OutputsGoverning maximum and minimum combination, with the substituted equation
Table of all active combinations with limit state, clause, expression and total
Number of active combinations

Worked example

Worked example coming soon.

Limitations and assumptions

  • Importance factors are assumed already applied (I = 1.0).
  • One generic load effect at a time (all axial, or all moment) in one consistent unit.
  • Combinations whose principal load is zero are dropped.
  • The SLS factors and the temperature and shrinkage factor are provisional in the app. Verify them against the code tables before relying on SLS results.

These calculators are aids, not a substitute for engineering judgment. Check results independently and against the governing code edition before relying on them.

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