ABSTRACT
ABSTRACT Current structural standards like the Eurocodes do not provide a coherent framework for design or assessment of structures under temporary use such as ancillary construction systems. In the light of comparatively high failure rates on record, this situation requires improvement, especially with a view to avoid gross human errors. In addition, appropriate target reliability levels for temporary structures are needed. The reliability requirements for temporary systems put forward in the present study seek to ensure the same acceptable risk levels per unit of time as for permanent structures in the current best practice. The results obtained show that the target reliability index for structural members rises significantly with declining risk exposure times. Conversely, the design values for variable actions may be lowered in keeping with the duration of construction, as illustrated in a case study, the analysis of a movable scaffolding system for the erection of a continuous prestressed concrete bridge girder.
