Evaluation of sewer network resilience index under the perspective of ground collapse prevention.

Generally, when evaluating the resilience of infrastructure, the four properties of resilience (robustness, rapidity, resources, and redundancy, 4Rs) are widely considered. However, there is little research on the resilience assessment of sewer networks. Therefore, to establish a framework to evaluate sewer network resilience under the perspective of urban ground collapse prevention, this study considers the 13 second-level detailed indicators corresponding to the four first-level indicators (4Rs) based on literature reviews and experts' opinions. An analytic hierarchy process (AHP) is used to obtain relative weights of each indicator and a weighted sum method (WSM) is used to evaluate the sewer network resilience index (SRI). The evaluation system is applied to eight small blocks of selected drainage areas in Seoul, South Korea, and the SRI of eight small blocks are computed. This study could help the sewer management department to make decisions and manage sewer network assets that enhance the resilience of the sewer networks.