A group load combination has load factors for every non-lateral loading and for one single lateral loading type.

Effectively, a group load combination's results are the envelope of all the results from N invisible single load combinations, where N is the number of loadings for the given lateral loading type.

A linear group load combination has a standard and alternate load factor for every non-lateral loading, and a standard and alternate load factor for the selected lateral loading type. It never has zero tension iterations.

A zero-tension group load combination has a single load factor for every non-lateral loading, and a single load factor for the selected lateral loading type. It has zero-tension iterations as necessary for invisible (internal) component load combo, and will be the envelope of all of the component load combos combined. It never considers pattern loading.

The following figure is intended to explain the ramifications of load combination type selection.

Refer to Summary of load combination types for more information.