Risk-informed design and safety assessment of structures in a changing climate: a review of U.S. practice and a path forward

AbstractStandards for the design of bridges, buildings and other infrastructure specify design loads for climatic hazards such as temperature, snow, wind, and floods based on return periods presented in maps or tables that account for regional differences. These design loads were developed from statistical analyses of historical hazard data under the assumption that the past is representative of the future. Climate change may affect the frequencies and intensities of environmental hazards which, depending on regional variations, raises questions as to whether structures designed to current specifications will meet minimum safety standards over their future service lives. This paper critically appraises issues related to using historical hazard data for future designs. It reviews basic principles of uniform reliability, that modern design codes use as the basis for ensuring minimum levels of safety, describing the relationship between hazard return periods, structural reliability, risk and the maximum loads expected within a structure’s service life. Simple examples involving wind effects on structures demonstrate how to calibrate structural design hazard maps for climate-related extreme events to meet the minimum standards of safety implied in current specifications. The paper also introduces a possible practical approach to account for climate change when designing new structures and assessing the safety of existing facilities.Keywords: BridgesBuildingsclimate changehazardsprobabilityreliabilitystructural engineeringstructural safetywind AcknowledgmentsThe authors are grateful for the fruitful technical discussions by the project team assembled by Task Group 2 (TG2) of the ASCE/SEI Technical Council on Life-Cycle Performance, Safety, Reliability and Risk of Structural Systems. The authors also acknowledge the contributions of Prof. Naresh Devineni who assisted with the analysis of the wind data set.Disclosure statementNo potential conflict of interest was reported by the author(s).Notes1 Loads due to normal service or environmental effects vary in time, and it is not meaningful to discuss their probabilistic probability distributions or statistical parameter without providing a time frame of reference. Following customary usage, this paper refers to this time frame as a service life; this does not imply that the structure is designed or warranted for this period of time.Additional informationFundingThe work presented in this paper was motivated by an ASCE/SEI Special Project on the Effect of Climate Change on Life-Cycle Performance, Safety, Reliability and Risk of Structures and Infrastructure Systems that the authors participated in. The project was organized by the ASCE/SEI Technical Council on Life-Cycle Performance, Safety, Reliability and Risk of Structural Systems.