Introduction to the State of the Art Collection: Risk-Based Lifecycle Performance of Structural Systems

Lifecycle performance, safety, reliability, and risk of civil infrastructure systems have become emergent issues in recent years owing to recurring natural and human-made disasters, the infrastructure crisis, sustainability issues, and global warming. Management of aging civil infrastructure involves significant expenditures, and at a time of constrained public resources, requires difficult decisions to establish priorities for maintenance, rehabilitation, and replacement. Dealing with uncertainties is an inevitable part of the management process. Decisions regarding requirements for design, continued service, rehabilitation, or replacement must balance conflicting requirements such as cost and performance. This can only be achieved through proper integrated risk management planning in a lifecycle comprehensive framework. The recent ASCE report, Civil Engineering Body of Knowledge for the 21st Century: Preparing the Civil Engineer for the Future (ASCE 2008), identified risk and uncertainty as one of the desired technical educational outcomes for the future practice of civil engineering.

In recognition of the need for risk-informed approaches to civil infrastructure design and management, the Structural Engineering Institute (SEI)-ASCE Technical Activities Division approved the formation of the Technical Council on Life-Cycle Performance, Safety, Reliability and Risk of Structural Systems in October 2008. The purpose of the Technical Council is to provide a forum for reviewing, developing, and promoting the principles and methods of lifecycle performance, analysis, design, construction, assessment, inspection, maintenance, operation, monitoring, repair, rehabilitation, and optimal management of civil infrastructure systems under uncertainty. The Technical Council consists of three task groups. Task Group 1 on Life-Cycle Performance of Structural Systems promotes research and applications of principles of safety and reliability in the assessment, prediction, and optimal management of lifecycle performance of structural systems under uncertainty. Task Group 2 on Reliability-Based Structural System Performance Indicators advances the development and utilization of reliability-based system performance indicators for structural safety, functionality, and robustness. Task Group 3 on Risk Assessment of Structural Infrastructure Facilities and Risk-Based Decision Making facilitates research and applications of principles of risk assessment and risk-based decision making in structural engineering.

The Technical Council is the central forum within the Structural Engineering Institute to promote important directions for research and applications of lifecycle performance assessment and risk-informed decision making in structural engineering. Consistent with its charge as a newly formed technical council and as one of the first council-wide activities coordinated among its three task groups, the council initiated a review and critical appraisal of the state of the art in performance indicators for members and systems, lifecycle performance evaluation and maintenance under uncertainty, decision making for sustainable and resilient infrastructure, and risk communication. This review and critical appraisal led to the special collection of the following papers, which represents the archival work product of the Technical Council for the first 5 years of its existence:

These five papers have been reviewed by the membership of the Technical Council and by the editorial board of the Journal of Structural Engineering. Collectively, they represent the consensus as to the current state of the art in lifecycle performance assessment and risk-informed decision making in structural engineering. The ideas in this collection span multiple scales, from components to systems to networks of systems. They provide support for decisions in many contexts: addressing multiple hazards, developing performance guidelines and standards, facilitating future novel materials, structures and infrastructure configurations, and achieving cost-effective community resilience.

The structural engineering community is moving toward more rational risk-informed approaches to structural engineering. The new paradigm of performance-based engineering provides additional motivation for the adoption of such approaches; and it is a novel way of approaching new design and construction technologies and for tailoring structural design to meet changing public expectations after natural and human-made disasters. Recent advances in lifecycle engineering and performance assessment, reliability analysis, and risk communication place performance classification on the basis of acceptable risk within reach. The papers in this special collection provide technical support for this move, and hopefully, they will engender a lively debate on prospects for their implementation in structural engineering practice.