The programs allow defining four design situations, which may differ by the analysis coefficients. These are:
- Permanent design situation - the most common situation and type of verification, adopted when proving the safe design of a structure for the assumed lifetime.
- Transient design situation - can be used for temporary structures (i.e. construction stages). As a rule, lower safety is required in comparison to the permanent design situation.
- Accidental design situation - adopted for extraordinary loads (e.g. blast, vehicle impact, flood, fire, etc.). The values of partial factors are typically equal to one.
- Seismic design situation - applied to the analysis of earthquakes. It might seem similar to the accidental design situation, but for an earthquake higher safety is sometimes required. In some countries, the required safety is even the same as for the permanent design situation.
LRFD introduces new types of design situations (Strength I, Service I, Extreme I).
Safety coefficients and partial factors are specified in the analysis settings.
The corresponding design situation for a given construction stage is selected in the "Stage settings" frame.
Selection of design situation