Development of cladding contribution functions for seismic loss estimation

Abstract

One method to rapidly estimate seismic losses during the structural design phase is to use contribution functions. These are relationships between expected losses (e.g. damage repair costs, downtime, and injury) for a wide range of building components (e.g. cladding, partitions, and ceilings) and the building’s response. This study aims to develop contribution functions for common types of cladding used in different types of buildings considering damage repair costs. In the first part of this study, a building survey was performed to identify types and quantity of cladding used in residential, commercial and industrial buildings in Christchurch, New Zealand; where it was found that the most common cladding types are glazing, masonry veneer, monolithic cladding and precast panels. The data collected during the survey was also used to develop cladding distribution (i.e. density) functions. The second step involved identifying fragility functions from relevant literature which are applicable to the cladding detailing used in New Zealand. The third step involved surveying consultants, suppliers and builders on typical repair/replacement cost. Finally, Monte Carlo simulations were performed to combine the cladding density function with the fragility functions and the repair cost for each type of cladding to derive contribution functions for various types of cladding and building usage. An example (case study) is provided to demonstrate its usage.