Experimental Studies to Investigate Merging Behaviour in a Staircase

The quantification of merging flows and the factors that influence evacuee merging behaviour are important considerations in our understanding of emergency evacuation of particularly high-rise buildings, and essential for better escape route design and evacuation modelling. This paper presents the results of three evacuation studies to investigate merging flows and behaviours on stairs. Stair:floor merging ratios are provided together with specific flows from the floor and stair. The potential influence of the geometrical location of the floor relative to the stair and the occupant population are discussed. The results indicate that, despite differences in the geometrical location of the door in relation to the stair and the relative stair/door width, the merging was approximately 50:50 across the duration of the merge period in each of the buildings studied. Differences in merge patterns were however evident throughout the merge periods in each of the buildings, particularly in the case where the floor occupants approached adjacent to the incoming stair, in which case floor occupants took priority during periods of slower movement. The occupant characteristics were also found to have a potential influence on merging, with very obvious deference behaviour of a few individuals dictating the merging in a mixed occupancy building. The studies highlight the potential influence of geometrical location of floor relative to the stair, relative door/stair widths and population characteristics on merge patterns and indicate that much more work is required in this area