Logic Tree Analysis of Secondary Nonstructural Systems with Independent Components

Abstract

The seismic performance of a nonstructural secondary system depends on the performance of each component of the system, and on the way in which the components are connected. The performance of each component is commonly described using fragility curves. Logic trees may be used to describe the way in which the components are connected. The use of logic tree analysis for secondary systems is briefly reviewed, and the method extended to allow the determination of the sensitivity of the system failure probability to the failure probability of any component of the system. An approximate method is proposed to find confidence intervals for the failure probability of the system, given uncertainty in the failure probability of each component. The method was found to give good results.