ABSTRACT
Reliability-based concepts are nowadays widely accepted in structural design. However, before such concepts can be effectively implemented, the actual design problem often needs to be considerably simplified. This is mainly due to two reasons. First, in their simplest formulation reliability-based procedures require the structural performance to be represented by explicit functional relationships among the load and the resistance variables. But, unfortunately, when the structural behavior is affected by several sources of nonlinearity, as always happens for concrete structures, such relationships are generally available only in an implicit form. Second, for structural systems with several components, a complete reliability analysis includes both component-level and systemlevel estimates. Depending on the number and on the arrangement of the components, system reliability evaluations can become very complicated and even practically impossible for large structural systems.
