The design life time is the minimum time [years] the structure should be able to fulfill its purpose. EN 1990 Table 2.1 gives the following recommendations:
|Design working life category||Indicative Design lifetime [years]||Examples|
|2||10-25||Replaceable structural parts, e.g. gantry girders, bearings/td>|
|3||15-30||Agricultural and similar structures|
|4||50||Building structures and other common structures|
|5||100||Monumental building structures, bridges, and other civil engineering structures|
The characteristic values of the variable loads mentioned in EN 1991 assume a design life time of 50 years. So if a structure has a design life time of 20 years, the chance that the variable load reaches that 50-year maximum is smaller. And when a structure has a design life time of 100 years, the chance is larger. Eurocode allows you to correct (decrease or increase) the value of the variable loads based on the design life time:
- wind loads: EN 1991-1-4 §4.2 remark 4
- snow loads: EN 1991-1-3 Annex D
- temperature loads: EN 1991-1-5 Annex A.2
- variable loads on floors (only in The Netherlands according to NEN-EN1990 art. A1.1 (2))
- The National Annex may provide a more detailed table (which slightly different values) than the one listed in this article.
- The Design Life Time can be entered in the Load Group dialog. Diamonds will automatically adjust the partial safety coefficients.
- Diamonds will take the influence of the design life time on the wind/ snow loads into account if the user checks the revant option in the Terrain parameters dialog ( and )
- Diamonds cannot take the influence of the design life time on the temperature loads into account.
- Diamonds will automatically take the influence of the design life time on the variable floor loads into account by adjusting the partial safety coefficients (only for National Annex of The Netherlands).