NCEER-94-0023 | 8/1/1994 | 172 pages
TOC: The table of contents is provided.
Keywords: Reliability Analysis, Design Criteria, Code Provisions, Reliability-based Design, Structural Safety, Uncertainty, and Design Procedures.
Abstract: The design of buildings and structures for seismic loads are traditionally based on the performance of structures in past earthquakes. Although the large uncertainty in the earthquake loadings has long been recognized by engineers, it has not been fully accounted for in code procedures other than in the selection of a design earthquake. Since the design earthquake is used in conjunction with a series of factors to account for effects of structural period, site soil condition, inelastic behavior, importance of structures etc., the reliability and safety of the final design remains unknown and undefined. The recent sentiment of the research community and design professionals is that there is a need for development of design procedures based on consideration of the physics of the problem and explicit treatment of the uncertainties. Such procedures may be used as the basis for development of the next generation of buildings codes. In this report, the theory and methodology that can be used to formulate such a design procedure is presented. A brief review is given of the theoretical background of reliability analysis and reliability-based design, followed by an examination of the safety considerations in representative current code procedures as well as the reliability of buildings designed in accordance with such procedures in different countries. Finally, a bi-level, performance-based design procedure is proposed in which desirable reliabilities can be implemented against both unserviceability and ultimate failure.