ABSTRACT
Civil infrastructure systems are exposed to various types of human-made, environmental, and climatic hazards within their service lives. Reliability-based approaches and probabilistic risk-informed methods have long been used for assessing the safety of such systems and developing design standards and specifications to account for the random nature of these hazards, their intensities and rates of occurrence, and possible compounding effects. Specifically, current design standards provide reliability-calibrated design load maps and tables as well as load combination factors for use in engineering practice during a structure’s safety check process. These maps and associated procedures are based on historical data assuming that the underlying processes are unchanging over time where observed variations in the historical data are only random oscillations around underlying stationary statistical properties. However, ageing processes, growth in economic activities, and climate change are causing increases in the frequencies and intensities of human-made and environmental hazards, raising the risk to infrastructure systems and their users.
This presentation reviews the fundamental principles behind structural code developments and their underlying assumptions. It also examines analytical methods to assess the safety of structural systems accounting for the nonstationary nature of hazards. The presentation discusses approaches for adjusting current structural design specifications in view of anticipated climate change scenarios. A numerical example illustrates the application of these approaches during the safety assessment and the design of structural systems.
