Risikoorientierte Bemessung von Tragstrukturen - Geplante Nutzungsdauer

Risk oriented structural design - Design working life.

The Eurocode DIN EN 1990: 2010-12 [1] requires in Clause2.1 (1)P that: "A structure shall be designed and executed in such a way that it will, during its intended life, with appropriate degrees of reliability and in an economical way, sustain all actions and influences likely to occur during execution and use, and remain fit for the use for which it is required." Special structures such as agricultural buildings, horticultural greenhouses, temporary and fairground structures as well as solar and wind energy structures usually have appreciably lower design lives than normal buildings. The Eurocode provides for a classification according to the structural design life. The economical optimisation can occur by adjusting the time variable characteristic actions to the design life, so that the required level of reliability can be maintained over the design lifetime. If necessary, additional requirements can be made regarding safety of persons, where large crowds are likely. This article explains the background and derivation of modification factors for the design life for the characteristic actions due to snow, wind and temperature. For traffic and live loads as well as exceptional actions such as impact loads and earthquake, some guidance is given.