Finite Element Reliability Methods in Earthquake Engineering Practice

The field of earthquake engineering is rapidly moving towards the use of sophisticated computational methods in engineering practice. This development is motivated by improved capabilities to numerically simulate nonlinear structural behavior during strong ground motion and the observation from recent earthquakes that the actual performance implied by simplified design guidelines is unclear. In this paper, the use of finite element reliability methods to further the transition towards performance-based engineering is discussed. Possibilities and remaining difficulties are discussed. Emphasis is put on the need to take all sources of uncertainty into account. A key element in the methodology is the use of newly developed techniques for time-variant reliability analysis to compute the probability of excursion of nonlinear response over a threshold during a time interval. This problem is of primary concern in earthquake engineering. Furthermore, the benefits of the parameter sensitivity and importance measures available in finite element reliability analysis are stressed.