The user can define a number of load groups, which can be assigned as permanent, stress, temporary, seismic or accidental. Every load group contains one or more earlier defined load cases. Depending on the active code, different partial safety factors could be defined. The program will then automatically combine and calculate every possible load combination in order to find the most unfavourable load position for the variable loads.

Load groups defined as permanent will be present in all load combinations and if a load group contains more then one load case they will never be simultaneously present.

Note: As the calculation requires the principal of superposition when load groups are used, it is not possible to use the option Consider cracking as this requires a non-linear calculation.

The calculation method vary from standard to standard (the Code independent standard doesn’t support load group calculations). For EuroCode (EC2), considering all defined load groups the load combinations will be created in the following way.

Ultimate Limit State

Design situations with only one variable action Qk1

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Design situations with two or more variable actions Qki

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Serviceability Limit State

Design situations with only one variable action Qk1

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Design situations with two or more variable actions Qki

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In this state the deformations and crack widths will be calculated. In the example below the way of producing load combinations is exemplified for a plate but the method used applies also for walls.

Example

A plate with four parts. The load case StruDL_P and SoilDL_P acts on the entire plate while the variable loads Q1_T and Q2_T acts on the respective parts of the plate. We set the Combination method to “EC0 6.10.a,b”.

We define the first two load groups with the name G-Struct and G-Soil. It will contain the load case StruDL_P and SoilDL_P, which are defined as permanent with favourable safety factor 1.00, unfavourable safety factor set to 1,35 and Xi factor to 0.9. Then we define two load groups LG1 and LG2 where we put load cases Q1_T and Q2_T respectively. These groups are all defined as temporary with the safety factor set to 1,5, the same time factor (Psi 0) to 0,5 and the other factors (Psi 1 and Psi 2) are 0.0. The program will now create and analyse the following 27 load combinations:

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