A user-centered, earthquake risk-informed approach to valve placement optimization in urban natural gas distribution networks

Urban natural gas distribution networks are critical infrastructure systems, and improving their post-earthquake functionality is important for strengthening societal disaster resilience. This study proposes an earthquake risk-informed optimization model for isolation valve placement in urban natural gas distribution networks. The model explicitly captures earthquake-induced cascading functionality loss caused by the isolation of damaged pipeline segments that disconnect adjacent undamaged components. It is formulated as a multi-objective optimization problem that balances the number of valves, reflecting installation cost and leakage risk, against expected post-earthquake functionality loss under different earthquake scenarios. A flexible weighting scheme is incorporated into the functionality-loss metric to represent service priorities among end users, such as emergency facilities, during post-disaster operation. The proposed framework is applied to a case study in a Chinese city under a set of representative earthquake scenarios. The results show that the optimized valve placement can substantially reduce expected post-earthquake functionality loss and that the distribution of service benefits among end users can be adjusted in accordance with decision-maker priorities.