Restoration modelling of water network under seismic hazard: Role of electrical and power network

The socio-economic wellbeing of a community depends on the proper functioning of its critical infrastructure system. Two most important critical infrastructure systems i.e., Water Network (WN) system, and Electrical and Power Network (EPN) system are crucial for the full functioning of the households, and socio-economic wellbeing of its citizens. After an extreme event, the functionality of the households will be reduced due to the damage in the WN and EPN. The functionality of the WN may also depend on the recovery of the EPN and should be considered for better estimates of the functionality recovery of interdependent critical infrastructure system. In this paper, the restoration modelling of WN is assessed under a maximum considered seismic hazard scenario, considering the dependence on the EPN network. The fragility and consequence functions are utilized for the damage and repair time assessment of each component. The repair times for each component are evaluated and the total repair time of the WN and EPN is determined. The WN and EPN restoration modelling is assessed through network models where the nodes represent the sub-components of a network and edges represent the connection restoration. In the considered example, the WN is fully repaired in 8 days after an earthquake event, while the EPN is fully repaired in 10 days. The WN will therefore be fully functional after 10 days since the power plant component of WN requires electricity from EPN network to pump water form reservoir to the water tank. It is therefore important to consider the dependencies of WN on the EPN for better estimates of functionality recovery of critical utilities to the households.