Extraordinary Live Load in Office Buildings

Abstract

Loads due to extraordinary events are investigated using data from the Sydney live‐load survey. A total of 1,989 extraordinary events of normal crowding, emergency crowding, and furniture stacking are studied. Parameters for a multiple extraordinary load model are obtained from the actual survey data. It is observed that not just the number of extraordinary load cells but all other parameters are area dependent. The mean and standard deviation of the number of people in a crowd for both normal crowding and emergency crowding decrease with decreasing floor area. Load due to furniture stacking shows a similar trend of variation. The numbers of load cells for the three types of extraordinary events are also observed to be different. Data from the present survey are compared with those from previous surveys. Present parameters are compared with values assumed by previous investigators. Extraordinary loads are predicted by using the extraordinary load model with the present parameters. They are observed to be, in general, 30% larger than values obtained using parameters assumed by previous workers.