A Markovian framework for multi-hazard life-cycle consequence analysis of deteriorating structural systems

Abstract

Multiple-hazard (or simply multi-hazard) interactions are either disregarded or addressed inadequately in most existing computational risk modelling frameworks for natural hazards, leading to inaccurate life-cycle consequence estimates. This, in turn, can lead to ineffective risk-informed decision-making for disaster-mitigation strategies and/or resilience-enhancing policies. Probabilistic multi-hazard life-cycle consequence (LCCon) analysis (e.g., assessment of repair costs, downtime, and casualties over an asset�s service life) enables optimal life-cycle management of critical assets under uncertainties. However, despite recent advances, most available LCCon formulations fail to accurately incorporate the damage-accumulation effects due to incomplete (or absent) repairs in between different hazard events. This paper introduces a Markovian framework for efficient multi-hazard LCCon analysis of deteriorating structural systems, appropriately accounting for complex interactions between hazards and their effects on a system�s performance. The proposed framework can be used to test various risk management and adaptation pathways. Specifically, the Markovian assumption is used to model the probability of a system being in any performance level (e.g., damage or functionality state) after multiple hazards inducing either �shock deterioration� or �gradual deterioration�, as well as after potential repair actions given such deteriorating processes. The expected LCCon estimates are then obtained by combining the performance level distribution with suitable system-level consequence models. The proposed framework is illustrated for a case-study reinforced concrete building considering earthquake-induced ground motions and environmentally-induced corrosion deterioration during its service life.