Load Combinations
Actions of loads that act simultaneously are introduced into the analysis with the help of load combinations defined in EN 1990 Basis of Structural Design. Most of the loads are considered as permanent. Surcharges and input forces can be specified as variable load. The program automatically determines the values of individual partial factors depending on whether a given load acts in favor or unfavorably.
By default the variable loads are considered as primary. Nevertheless, the "Verification" and "Dimensioning" frames allow to specify the variable loads as secondary - such a load is then pre-multiplied by the corresponding coefficient reducing its magnitude. Providing that all loads are considered in the basic combination as secondary the program prompts a warning and the verification is not accepted.
Four types of combinations can be specified in the frame "Stage settings":
Persistent and transient design situation:
where: | Gk,j | - | characteristic value of jth permanent load |
γG,j | - | partial factor of jth permanent load | |
Qk,i | - | characteristic value of secondary ith variable load | |
Qk,1 | - | characteristic value of primary variable load | |
γQ,i | - | partial factor of ith variable load | |
ψ0 | - | factor for quasi-permanent value of variable load |
Accidental design situation:
where: | Gk,j | - | characteristic value of jth permanent load |
Qk,1 | - | characteristic value of primary variable load | |
ψ1,i | - | factor for frequent value of variable load | |
ψ2,i | - | factor for combination value of variable load | |
Ad | - | design value of extreme load |
Seismic design situation:
where: | Gk,j | - | characteristic value of jth permanent load |
Qk,i | - | characteristic value of secondary jth variable load | |
ψ2,i | - | factor for quasi-permanent value of variable load | |
AEd | - | design value of seismic load |
Load partial factors and combination coefficients are introduced in the "Partial factors" dialog window.
Input of secondary loads