Resilient infrastructure futures : an aetiological analysis of lifeline system failures since 2000 for enhancing the resilience of next-generation infrastructure design
Keywords: Engineering.
Mechanical Engineering.

Lifeline systems, as a subset of all infrastructure systems, are critically important for the permanent inhabitation of urban environments. These lifeline infrastructures are planned and constructed in service to current and future urban populations, and their persistent and reliable operation is of paramount importance for satisfying urban metabolisms while maintaining basic life-support for urban dwellers. While most components of infrastructure systems are materially fixed within specific environments, the performance of lifeline systems enables flows of critical resource units including communication (mHz), energy (kWh), transportation (miles or trips), water (MGDs), while also discharging units of waste (tons). Risks that pose a threat to the sustained and reliable operation of lifeline systems are characterized as hazards. Extraordinary efforts are required today of AECO infrastructural professionals to plan, develop, and implement the next generation of lifeline systems in recognition of demonstrated hazards and in anticipation of hazards not yet presented. To assist their work, and serve the health, safety, and welfare of urban dwellers, the larger goal of this investigation is to contribute new knowledge for enhancing the operational resilience of next-generation lifeline infrastructure solutions. The research path includes questioning the inventory of hazards and threats identified through field-based focus and methods, which may yield incomplete analysis and underscores a need to update, expand, and improve existing tactics for classifying demonstrated hazards responsible for inducing lifeline operational failures. A desired outcome of this design-actionable research is the generation of insights for reducing epistemic risk affecting lifeline systems. The research questions leading this investigation are: What are the causal agents responsible for inducing losses of effective use for lifeline infrastructure systems so far in the 21st century? How effectively can an aetiological examination of these lifeline failures improve prevailing methods of classifying infrastructure failure incidents? What are design-actionable insights for elevating resilience of next-generation lifeline infrastructure solutions today for use in uncertain and wholly unforeseeable futures? Structured as a full thesis, this investigation examines incidents of operational failures to five lifeline system types occurring worldwide between January 2000 - December 2022. The first contribution is a data set comprised of 1,200 lifeline failure incidents represented by hazard event, hazard event date, lifeline type, incident location, causal agent coded according to four tiers of classificatory description, failure extents, and up to three contributing factors. The second contribution is an aetiological analysis ("error taxonomy") identifying (271) distinct genera of contemporary hazards and threats historically responsible for inducing specific operational failures to lifeline systems so far this century. Through the construction of these research materials, the similarities and differences between hazard types are discerned into four updated classes titled Environmental Hazards, Mechanical Faults, Zoogenic Interventions, and Flow Compromises for improving visibility, awareness, and comprehension. This substantive assessment includes the theorizing of Flow Compromises as an emergent parent category deserving of equal classificatory consideration in this Anthropocenic era, and is shaped by observed quantitative and qualitative failures in the resource unit cycle of inflows, stocks, and outflows. This investigation concludes with the assertion of three evidence-based pathways for improving the resilience (or future-proofing) of next-generation lifeline infrastructure design.