I have generated the earthquake loads manually. How can I combine them according to the superposition rules of the standard?

Answer

If you have defined load cases with earthquake loads and can not combine them with the RF-/DYNAM Pro add-on module, you should not apply the automatic combinatorics for this. The following steps describe how to define the manual combinatorics:


  • Depending on whether you want to use the SRSS or CQC rule, you may have to activate it in the general data (only necessary in the case of the CQC rule). For the CQC rule, you have to activate additional parameters; this can be set in the load cases.

  • Create one result combination per direction. Add all load cases where you have defined earthquake actions in this direction. The type of superposition can then be defined in the calculation parameters.
  • Next, the directions are superimposed in further result combinations. For this purpose, the Eurocode 8, for example, specifies the 100/30% rule. To do this, add "and"  to the result combinations of the individual directions and change the factors to 1.0 for the dominant direction and 0.3 for the other directions. It is necessary to create always one result combination for each direction.

  • Finally, another result combination is created, which can then be used for the design. In this table, the earthquake loads are superimposed with the permanent and the imposed loads (creation of the unusual combination). Please note that the result combinations for earthquakes must be added with "or".

Keywords

Equivalent load Combination Earthquake Dynamic Result combination

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