Reliability Analysis on Capacity Design Rules for Steel Frames

Capacity design rules are applied to ensure the intended plastic behaviour of structures subjected to earthquakes. They need to cover scattering due to the seismic action and material strength. Recent evaluations of data of structural steel from European producers show for low steel grade an overstrength, which is higher than covered by the recommended value in DIN EN 1998-1. In this paper results of reliability analysis performed on this topic are presented. For this purpose a stochastic model for the seismic action was derived, which enables to perform the investigations via push-over analysis instead of time-consuming non-linear time history analysis. The main findings are discussed in the view of adjustments of design rules in DIN EN 1998-1 and European product standards, respectively.