Flow-based seismic resilience assessment of urban water transmission networks

In this study, a new framework of seismic resilience estimation for urban water transmission networks was developed. The proposed resilience estimation model consists of three phases: input earthquake generation, hydraulic analysis, and recovery of network facilities. In the earthquake generation phase, the uncertainty of the ground motion is determined using the spatially correlated seismic attenuation law. In the hydraulic analysis phase, a hydraulic simulation is performed in conjunction with EPANET analysis. In the recovery phase, network components are restored, and the performance of the recovered network is evaluated through hydraulic analysis. Then, the seismic resilience curve and recovery costs are calculated. For a numerical simulation, a MATLAB-based computer code was developed for pressure-driven analysis in EPANET simulation. To demonstrate the proposed model, an actual water transmission network in South Korea was reconstructed based on geographic information system data. The performance of the network system was evaluated according to two performance indices: system and nodal serviceability. Finally, the cost of repairing the network facilities and water loss are estimated according to earthquake magnitude and interdependency. Numerical results show that the recovery slope of the resilience curve tends to decrease as the earthquake magnitude and interdependency with the power facilities increase.