About Load Combination Generator
The load combination generator builds every factored load combination for a structure per Eurocode 0, ASCE 7 (both LRFD and ASD), and AS/NZS 1170.0. It is used by structural engineers to combine dead, live, wind, seismic, snow, and rain loads and find the governing case for design.
Enter the characteristic value of each load and choose a design standard; the tool applies the code load factors, sums the factored contributions for every combination, highlights the governing ultimate (ULS) and serviceability (SLS) cases, and shows a full table that updates as you edit the loads.
How It Works
- Add each characteristic load with its category (dead, live, wind, seismic, snow, or rain) and magnitude in kN, kN/m, or kPa.
- Select a design standard, which sets the partial load factors and the list of combinations to generate.
- Multiply each load by its factor in every combination and sum to get the total factored action for that combination.
- Find the combination with the highest total in each class and flag it as the governing ULS or SLS case.
Worked Example
Under Eurocode 0 with a dead load G = 10 and a live load Q = 5, combination 6.10a gives 1.35G + 1.05Q = 13.5 + 5.25 = 18.75, while 6.10b gives 1.15G + 1.5Q = 11.5 + 7.5 = 19.0. The tool flags 1.15G + 1.5Q as the governing ULS case at 19.0.
Formulas
- Factored combination total
S = sum(gamma_i * Q_i)- Eurocode 0 ULS (eq. 6.10b)
S = 1.15 * G + 1.5 * Q- ASCE 7 LRFD basic combination
S = 1.2 * D + 1.6 * L + 0.5 * (Lr or S or R)- ASCE 7 ASD wind combination
S = D + 0.6 * W
Standards & References
- Eurocode 0 (EN 1990)
- ASCE 7-22 (LRFD and ASD)
- AS/NZS 1170.0
Frequently Asked Questions
Which load combination standards are supported?
The generator covers Eurocode 0 (EN 1990) ULS and SLS combinations, ASCE 7-22 LRFD strength and ASD allowable-stress combinations, and AS/NZS 1170.0, applying each code load factors automatically.
What is the difference between ULS and SLS combinations?
Ultimate limit state (ULS) combinations use higher factors (for example 1.35G + 1.5Q) to check strength and stability, while serviceability limit state (SLS) combinations use near-unity factors for deflection and comfort. Eurocode 0 also splits SLS into characteristic, frequent, and quasi-permanent cases.
How is the governing combination identified?
The tool computes the total factored action for every combination and marks the one with the highest total in each class as governing, so you can design the member for the worst case directly.
What is the difference between LRFD and ASD in ASCE 7?
LRFD (Load and Resistance Factor Design) applies amplified load factors such as 1.2D + 1.6L for strength design, while ASD (Allowable Stress Design) uses service-level combinations such as D + L, so the two sets of combinations are not interchangeable.