Identifying Critical Links in Water Supply Systems Subject to Various Earthquakes to Support Inspection and Renewal Decision Making

摘要

Widespread damage of water supply systems during recent earthquakes clearly shows the need for seismic planning. However, water supply seismic planning is subject to uncertainties in location, magnitude, and resulting damage of earthquakes. This problem is further complicated by complex topology of water supply systems along with the use of different materials, joint characteristics, pipe diameters and soil corrosivities. The objective of this paper is to identify critical links of water supply networks subject to various earthquakes and find optimum renewal decision given resource constraints. The methodology comprises of four interconnected components: (1) Repair Rate Probabilistic Modeling; (2) Monte Carlo Simulation; (3) Hydraulic Damage Modelling; and (4) Resource Allocation Optimization. The first component calculates repair rate for each pipe in the network based on empirical fragility curves. Empirical fragility curves depend on the pipes' location, material, diameter, joint property and soil corrosivity. Monte Carlo simulation generates probabilistic damages (i.e., leaks and breaks) in the pipe network. The hydraulic model calculates serviceability index considering simulated damages. Resource allocation optimization model uses genetic algorithm to find the optimum renewal decision to maximize serviceability index given resource constraints. The proposed model was validated using a water supply network. The network consists of 117 pipes and 92 junctions. The results show that the proposed methodology outperforms the latest proposed methodology in the literature to identify critical links in a water network. The network serviceability index is used as the measure to compare the results with the latest proposed methodology in the literature.