Fragility of a Structure, System, or Component for Seismic Performance

摘要

Structural engineers, researchers, code committees, and regulatory bodies have become increasingly interested in performance-based design of structures, systems, and components (SSCs) in the past few years. This has been demonstrated by the publication of codes for the performance-based design of traditional buildings, and by publication of a consensus standard for evaluating the seismic performance of nuclear facilities. Performance-based design is an engineering approach, where the design process is structured to achieve performance requirements (limit states) specified by the owners for asset protection, and/or to meet a risk level, specified in regulations, to ensure adequate protection of public health and safety. The probability of unacceptable performance of an SSC, or of exceeding a given limit state, is determined by convolving the seismic hazard curve for the site of the proposed facility with the fragility curve of the SSC, defined as a conditional limit-state probability of occurrence, expressed in terms of a given earthquake ground motion demand quantity (e.g., spectral acceleration, spectral velocity). This paper examines a Monte-Carlo method of analysis to develop a fragility curve for a low-rise concrete shear-wall component of a building structure, using empirical equations based on tests, and theoretical equations based on the truss and arch mechanisms for shear failure. Results of the analyses are compared with the analytical results available in the literature, and the capacity based on the consensus building code standard, to gain insight into the potential safety margins.