A multi-step framework for measuring post-earthquake recovery: Integrating essential infrastructure System's serviceability in building functionality

Abstract

Measuring and predicting the functionality of buildings is a core aspect of community resilience analysis, which is jointly dependent on structural integrity and essential services provided by critical infrastructure systems. A functional building is one that is used for its intended services. This paper develops a multi-step community-level functionality analysis framework by modelling: (1) building functionality that integrates the building's structural performance, essential water and electric power service performance, and physical accessibility through road networks; (2) portfolio-level building recovery by aggregating functionality of buildings for an entire community; and (3) serviceability of infrastructure systems. Graph theory is applied to assess performance of infrastructure systems. The cascading effect of water pipe failure on the road network is modelled through geographic dependency analysis. Post-earthquake water demand changes due to household dislocation and return, and increased water service demand at essential facilities are captured to model the performance of the water network under stressed conditions. The framework also assesses household-level housing recovery and integrates results with physical damage repair to more holistically depict the functional recovery of buildings from the perspective that buildings must be occupied to be fully functional. The proposed framework is illustrated for a scenario earthquake for the virtual community of Centerville. Findings provide an up-to-date measurement of post-disaster functionality for buildings and critical infrastructure systems that can guide decision-makers during pre-disaster planning and post-disaster recovery. The example demonstrates that consideration of essential infrastructure services significantly alters the functionality of the built environment during the recovery process. For instance, power outages resulted in functionality loss of up to 75 % of physically operable buildings for as much as 14 days. Consideration of physical accessibility loss to nearest road segments resulted in a portfolio functionality drop of up to 9 % for 6 days, and partial water shortage significantly hampered the functionality of the impacted area, including the regional hospital. Approximately 3 % of households were unable to repair their damaged homes and became homeless. The proposed framework enables risk-informed decisions regarding long-term recovery at the community scale with inclusion of those living at the margins and most susceptible to long-term negative consequences from disasters.