The Climatic Action Uncertainty Chain

Inspired by the Alan G. Davenport Wind Loading Chain, first a uniform format for the modelling of climatic actions of snow, wind, thermal actions and atmospheric icing actions is presented in the form of a Climatic Action Loading Chain (CALC). The definition of the complete probabilistic loading chain is discussed providing the basis for a more reliable calibration of load partial safety factors. Finally, the concepts are applied to an example showing that the value of the partial factor strongly depends on the assumptions made during calibration, and that as a consequence the value of the reliability index may strongly differ from the target one.