Reliability of sprinkler system in Australian shopping centres –A fault tree analysis

Abstract The purpose of this research is to determine the reliability of sprinkler systems in shopping centres by utilising the fault tree analysis (FTA) method and the collection of data through a physical survey. As such, a comprehensive review of sprinkler systems in the low rise shopping centre buildings with less than four levels was conducted in two Australian cities: Melbourne and Adelaide. Data from eighteen buildings were collected and are presented in this paper. This study only includes wet pipe systems, as these are the most commonly found sprinkler system installations throughout Australia and New Zealand. Although Australian Standards and building regulations are taken as references, the methodology can be used in any other jurisdictions. The data related to the failure frequency, time required for repair and sprinkler downtime due to tenancy changes were collected during site surveys. This data has been used to carry out FTA to derive the likelihood of the failure of the sprinkler system. It is observed that the failure probability of a sprinkler system in Australian shopping centre buildings lies in a range of 1.4% and 9.8% (i.e. reliability range of 90.2% and 98.6%). Compared to a previous study on high-rise office buildings (Moinuddin & Thomas, Fir Saf J. vol 63 pp 52–68, 2014), the reliability of shopping centres is found to be 3%–4% higher. Similar to high-rise office buildings, sprinkler head's failure and isolation of the main stop valve during tenancy upgrades have significant effects on the reliability of the sprinkler system. However, more regulated sprinkler isolation and better maintenance of other components in the shopping centres result in better reliability.