A Unified Risk-Based Framework for Assessing Sustainability and Resiliency of Civil Infrastructure

As of February 2019, the National Aeronautics and Space Administration (NASA) has reported since 1880 the average global temperature has increased 1°C, with the warmest year on record being 2016. As the years continue to pass, it is becoming more evident that climate change is occurring, which is known to be a catalyst for climatic weather events. Statistically speaking, these events are more prevalent, and catastrophic exemplified as hurricanes, earthquakes, flooding, and fires. In addition to the increase of potentially catastrophic events, society as a whole has become more conscientious in the use and preservation of natural resources, waste generation, and energy consumption. As the overall population continues to grow, the need for safe, secure and sustainable infrastructure increases. Civil infrastructure must be assessed to measure the level at which it will withstand impact from a catastrophic event, as well as how it is utilizing precious resources and energy. In consideration of these previously mentioned issues, several federal agencies, companies, and researchers have put forth an effort to measure and quantify the ability of civil infrastructure to withstand climatic catastrophes. Also, metrics to quantify sustainable construction are increasingly used as a common tool for infrastructure design and development. Most sustainability metrics consider the qualities of a system that revolve around the concept of sustainable development but fail to consider the resiliency of that system. Sustainability assessments are often discrete and will focus on one particular aspect or measure. Resiliency metrics are often overly complex and do not fully encapsulate the quality in a way that is pragmatic or useful to practitioners and engineers, or simply neglect sustainable construction methods. Proposed here is a framework that attempts to unify sustainability and resiliency assessment of geotechnical infrastructure, by considering the risk of failure given the probability of a catastrophic event. The framework is developed for use on geotechnical engineered systems, specifically an earthen dam used for flood control. A Bayesian analysis is used to determine the probability of failure given the occurrence of a catastrophic event, in conjunction with both a resiliency assessment, and sustainability assessments. This is to ensure that the sustainability index is jointly dependent upon the changes in resiliency given the occurrence of a catastrophic event. Two separate failure modes that are possible at the location of the earthen dam were modeled to determine the flexibility of the framework. Failure modes include seismic events, and rapid-drawdown and both were modeled with their associated probabilities. Results from the assessment are represented as a single index value that is plotted on a cartesian coordinate system. It is of note that assessment of a particular form of infrastructure mandates analysis of particular failure modes, and changing the system then requires analysis of failure modes to that particular system. In order to fully encapsulate a unified framework for sustainability and resiliency, it was imperative that the thesis provided here focus on one particular infrastructure system, which was chosen to be an earthen dam