Resilience of the Built Environment: A Methodology to Estimate the Downtime of Building Structures Using Fuzzy Logic

Natural and man-made disasters have caused a significant impact on residential buildings worldwide. The damaged buildings stay unoccupiable for a period of time, called the downtime. This chapter introduces a new methodology to predict the downtime and the resilience of building structures using Fuzzy logic. Generally, the downtime can be divided into three main components: downtime due to the structural and nonstructural damage (DT1); downtime due irrational delays (DT2); and downtime due to utilities disruption (DT3). DT1 is defined by assigning a pre-defined repair time to each building component given the number of workers assigned. DT2 and DT3 are estimated using the REDi^TM Guidelines, which provide good estimates of the delays incurred by irrational components and utilities disruption. The Downtime of the building is finally obtained by combining all three components. Following the downtime estimation, the resilience of the building is estimated by combining the downtime of the building (DT) and the building damage level. The latter is assessed using a rapid visual screening form designed by the authors. As a case study, the methodology has been applied to a residential building where the 1994 Northridge earthquake is selected as the hazard event.