Structural reliability and performance-based engineering

Civil infrastructure facilities must be designed to withstand demands imposed by their service requirements and by natural environmental events. In the past four decades, structural reliability methods have matured to the point that they now provide the framework for addressing safety and serviceability issues in modern codified structural design, and most countries have adopted such methods for code development. While the normal design process usually results in a constructed facility with a degree of integrity that is also available to withstand challenges from unforeseen events, events outside the traditional design envelope may result in severe damage or economic losses and, in extreme instances, precipitate catastrophic collapse. In an era of heightened public awareness of infrastructure performance, performance-based engineering (PBE) offers a new paradigm that may allow structural engineers to meet these challenges and to better match building design with owner, occupant and social performance expectations. Successful implementation of PBE will require understanding and acceptance of the supporting quantitative structural reliability risk assessment methods and risk-informed decision tools summarised in this paper.