Review of Risk Management in Civil Infrastructure by Mohammed M. Ettouney and Sreenivas Alampalli

Risk has always been difficult to define. Many define risk as simply the possibility of the occurrence of undesirable events. When risk is defined in this fashion, either subjectively or objectively, it only gives the reliability component of risk and ignores the associated consequences. In this book, the authors define risk in a manner that is consistent with its historical uses in other communities (such as insurance or finance), while being compatible with civil engineering needs and practices. At the same time, the authors also recognize and incorporate certain important and essential practices in civil engineering, such as field inspection and resilience. They argue that this has the advantage of being accurate while permitting stakeholders to use the available tools of each paradigm interchangeably. Beyond definitions, the authors hold that the successful application of risk-based practices in civil engineering requires comprehensive handling. The first chapter introduces these definitions and gives a flowchart for the rest of the contents covered in the book. The authors note that the concept of risk should be used in a complete risk management framework that includes five complementary components: assessment, acceptance, treatment, monitoring, and communications. Five chapters of the book address each of these components in detail.

The second chapter of the work covers analytical risk methods. The authors state that the comprehensive method has the following requirements: “Realistic and accurate modeling linkages/interactions between variables; Accommodation of uncertainties associated with different variables; Accurate modeling of observations at any given time (snapshot or a time period); Accommodation of objective and subjective variables and pertinent combinations; Seamless accommodation of decision under uncertainty while accounting for all of the above attributes; Ease of modeling complex models; and Ease of changing, adding to, or trimming complex models.” Accommodating all these subjective and objective requirements is a difficult task; hence, the authors utilize a probabilistic graph network (GN) to meet them. The remainder of the chapter covers GN techniques that can be used in handling different risk management components.

The third chapter explores risk assessment using GN methods and weighted averages. Risk assessment examples for tunnels and mass transit stations are offered. In addition, the authors give examples showing risk assessments for earthquakes and bomb air blasts, as well as building security. This chapter also shows examples of resilience assessment while discussing its relationship with risk assessment.

Risk acceptance has always been a difficult issue in civil engineering. In the fourth chapter, the authors first cover wholly subjective and semisubjective (with some objective backing) acceptance thresholds and then show how to set risk acceptance thresholds in practical situations. Several examples show how to set risk acceptance thresholds in other practical cases, including setting deterioration risk acceptance and the establishment of risk acceptance while grandfathering an existing infrastructure system.

Risk treatment is the natural next step in a risk management–based process and is covered in Chapter 5. In this chapter, the authors differentiate between risk treatment and risk mitigation, with the latter as a subset of the former. They then proceed to subdivide the risk treatment process into three phases: choosing a treatment strategy, planning and prioritizing projects and solutions, and executing the strategy. The authors also show that the popular subjective-consequences-likelihood diagram approach to selecting a risk treatment strategy is not suitable and might lead to suboptimal decisions.

As infrastructure ages, risks increase due to deterioration or increased demand. In many situations, monitoring changing risks is not pursued as an integral part of a balanced risk management scheme. In Chapter 6, the authors address risk monitoring. Besides the conventional monitoring of just capacity or demands, they also discuss deterioration risk monitoring and forecasting, inference processes in risk monitoring, and the differences between risk monitoring and reliability monitoring.

Chapter 7 details risk communications, an often-forgotten component of risk management. This chapter helps readers recognize the importance of risk communications and offers tools that can aid them to incorporate risk communications techniques in their projects as well as research efforts. Risk communications are explored from both the technical and management perspectives. An objective example of communications efficiency in evaluating risk communications projects is offered in the end.

The authors provide numerous examples and case studies throughout the manuscript. Many of those examples are fairly practical and can be used, with appropriate modifications, by practitioners and decision makers. To focus on practical risk management–based applications, they devote the final chapter of the book, Chapter 8, to several case studies, including the progressive collapse of bridges, cascading effects during super storms, structurally deficient bridges, functional obsolescence, and suspension bridge security.

In summary, in this book, the authors fill a sorely needed gap in the civil engineering risk management literature by offering comprehensive and balanced coverage of the subject. As such, both researchers and practitioners can benefit from the book. Researchers can build on its numerous original ideas while owners can utilize its practice-oriented case studies to enrich their decision-making efforts.