Load combination classes

Combinations fall into nine different classes, with a number of options available for each of the classes:


Combination class	Description	Active	Strength	Service
Construction Stage	Describes the loading that will apply for the pre-composite stage design of composite steel beams.	N/A	N/A	N/A
Gravity	Automatically assigned to combinations consisting of gravity loadcases only (self weight, dead, slab dry, slab wet, imposed, roof imposed, snow).	On/Off	On/Off	On/Off
Lateral	Automatically assigned to combinations containing lateral loadcases (e.g. notional loads or wind), with or without gravity loadcases.	On/Off	On/Off	On/Off
Seismic	Automatically assigned to combinations containing seismic loadcases, with or without gravity and/or lateral loadcases.	On/Off	On/Off	On/Off
Seismic RSA	Automatically assigned to combinations containing seismic RSA loadcases, with or without gravity and/or lateral loadcases. Typically created by running the seismic wizard.	On/Off	On/Off	On/Off
Base Shear	Created by running the seismic wizard, This class is reserved for the Effective Seismic Weight (ASCE 7) or Seismic Inertia (Eurocodes).	On	N/A	N/A
Modal Mass	Describes the mass that will be considered during modal (vibration) analysis.	On/Off	N/A	N/A
Staged Construction	Describes the loading that will apply to each of the construction stage models considered in a staged construction analysis	N/A	N/A	N/A
Footfall Mass	Created in the footfall analysis view and describes the mass that will be considered during footfall modal analysis.	On/Off	N/A	N/A

Active: Selecting and clearing the option switches the combination on and off for analysis and design.
Strength: If the Strength option is not selected and the combination is active, the combination is not assessed for strength checks.
Service: If the Service options is not selected and the combination is active, the combination is not assessed for serviceability checks.