Uma, S.R. 2012 Achieving acceptable performance levels in the seismic design of buildings. Lower Hutt, N.Z.: GNS Science. GNS Science report 2012/24 18 p.
Abstract: Failures of structures during earthquakes, especially recent events, provide lessons to the structural engineering profession. In addition, they stimulate engineering professionals to revisit existing design provisions and to make improvements wherever necessary. More importantly, uncertainties associated with the occurrence of natural hazards, structural capacity and ability of existing buildings to withstand future hazards make the profession more challenging. A natural consequence of uncertainty is risk, and so a primary purpose of the structural engineering profession is to manage that risk and to maintain the safety of buildings and other facilities at socially acceptable levels. A well-established framework includes various components such as: (i) a building regulatory system to express the public’s expectations in terms performance and cost; (ii) supporting documents such as design standards that include loading and material standards, prescriptions of magnitudes of forces for design, and methods of analyses to determine resistance. The New Zealand Building Code adopts a performance-based approach and sets the objectives and goals related to functional and performance requirements of a building structure, including construction, demolition and alteration work. References are made to design standards and guidelines which include acceptable solutions and criteria for the design. However, the current design procedures are not able to fully address the performance expectation of the client or building owner in terms of acceptable levels of performance or acceptable levels of loss. This report discusses the present status of the performance-based approach adopted in New Zealand design practices, identifies gaps in implementing performance-based design, and the way forward to achieve tolerable impact levels in buildings under earthquake loading. (auth)