2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
Assessment of Resilience of Water Distribution Network against Seismic Hazards for Maintenance Planning


Author(s)
Ms. Sudipta Adhikary, Concordia University (Presenter)
Dr. Fuzhan Nasiri, Concordia University
Dr. Ashutosh Bagchi, Concordia University, Canada
Abstract

It is essential that water distribution networks (WDNs) remain performing undeviatingly following constrained to natural hazards, and it is considered vital in terms of seismic hazards, to keep maintaining structural integrity. Several studies on past earthquakes occurred in Vancouver, BC, have prompted notable destruction to WDNs, interpreting them as a potential reason for loss and damage from structural and economic perspective. Based on the behavior of underground water distribution pipelines, this paper suggests a method to quantify resiliency as easy-to-use metrics to improve the performance of water distribution network subjected to earthquakes. In cities like Vancouver, WDNs are prone to seismic hazards and are subject to regular refurbishment and repair. Following such circumstances, early evaluation of existing network’s seismic structural resilience is essential to carry out strategic planning for maintenance and replacement works. In this paper, resilience index is produced for the WDN of the study area (an extensive network consisting of 69,680 links) considering three scenarios of earthquakes ranging between MMI 7 to MMI 10 (very strong to severe). These scenarios are formed using empirical data of past earthquakes, which includes ground motion and break rates of lifelines and the estimated peak ground acceleration (PGA). All the neighborhoods in the study area are ranked from most resilient to least resilient based on index metrics. Maintenance scenarios for the least resilient neighborhood due to the extreme exposure of the event have been produced as maintenance map to improve the resiliency of the system, integrated with the geographical location using software ArcGIS. To build a practical and feasible replacement strategy, 12 maintenance planning with network map is created showing an increase ranges from 0.8% to 41.52% in the total resiliency of the network and an estimated 15.17% to 89.96% increase of the invulnerability in the network mains. Taking cost as a vital limiting agent in the replacement of WDNs, afterward, evaluation of robust replacement alternatives are performed to find out a cost-effective maintenance planning strategy.