Stochastic life-cycle sustainability analysis

During their life-cycle, engineering systems typically suffer from deterioration due to regular operation and exposure to extreme events and harsh environmental conditions. As a result, regular or exceptional recovery strategies are often required to restore the system to a target safety and functionality level. There is a need to evaluate the associated impact of such strategies on the life-cycle sustainability of engineering systems. This paper proposes a novel stochastic formulation, named Stochastic Life-cycle Sustainability Analysis (SLCSA), for evaluating the sustainability of engineering systems throughout a time horizon of interest. In the SLCSA, the sustainability of the system is evaluated in terms of its environmental impact, which includes the impact of the construction, operation processes and recovery strategies that are associated with the various components of the system. The formulation proposes state-dependent stochastic models that capture the effects of gradual and shock deteriorations in the evaluation of the environmental impact of the system as well as the resilience of the system described by the recovery strategies. Moreover, the formulation accounts for the relevant uncertainties, such as those in the external conditions (e.g., environmental exposure and potential hazards), and those in the environmental emissions, associated with the materials and energy used throughout the system life-cycle. As an illustration, the proposed analysis is used to evaluate the life-cycle sustainability of a typical reinforced concrete (RC) bridge.