Safety Assessment of a Steel Frame Using LRFD and SBRA Methods

Abstract

Powerful computers on each designer’s desk, improvements in simulation technique, and advances in the reliability assessment theory make it possible to consider a transition from prescriptive concepts, such as partial factor design (PFD), to fully probabilistic concepts applicable in design practice, such as the feasible simulation-based reliability assessment (SBRA) method. Using a pilot example, the main differences between the PFD assessment procedure and SBRA procedure are demonstrated and described. Attention is focused on the substance of individual steps starting with the assignment (including a representation of loading, mechanical, and geometrical properties of the structure and characteristics of imperfections) and concluding the comparison with safety limits expressed vis-à-vis PFD by a ratio of demand and capacity (to be less than 1.0) and regarding SBRA by comparing the probability of failure