Load Combination Sets

Several standard building code load combinations are built into ConcreteSection. You can also define custom combinations in the Load Combinations tab of the Load Case Manager. Use service-level combinations to review service condition results. Use strength-level (LRFD) combinations to check section capacity, applying strength reduction factors (ϕ) for ACI and CSA, or partial safety factors (γ) for Eurocode design.

Importing Load Combinations

Custom factored load combinations can be imported from the clipboard using the Import From Clipboard button in the Load Combinations tab in the Load Case Manager. Text must be tab delimited and copied to the clipboard in the following format:

     {ComboName} {Factor} {ServiceCaseName} {Factor} {ServiceCaseName2} …

For example:

     ComboName    1.2    D     1.6    L     0.5    Lr

     MyCombo      0.9    D     1.3    W

Seismic Criteria

To correctly generate load combinations that contain seismic loads, several additional parameters are required. Please refer to ASCE 7, Section 12.4, for how these parameters are used in generating load combinations. It is important to note that these parameters (such as SDS and SD1) are only used to generate load combinations. For example, ASCE 7 says that Seismic Category A does not require the combined orthogonal direction combinations (e.g. X+30%Y), but Category D does. ConcreteSection does not automatically generate any loads, just the combination cases.