SpringerBriefs in Fire Series Editor James A. Milke For further volumes: http://www.springer.com/series/10476 Bryan L. Hoskins (cid:129) James A. Milke Study of Movement Speeds Down Stairs Bryan L. Hoskins James A. Milke Department of Fire Protection Department of Fire Protection Engineering Engineering University of Maryland University of Maryland College Park, Maryland, USA College Park, Maryland, USA ISSN 2193-6595 ISSN 2193-6609 (electronic) ISBN 978-1-4614-3972-1 ISBN 978-1-4614-3973-8 (eBook) DOI 10.1007/978-1-4614-3973-8 Springer NewYork Heidelberg Dordrecht London Library of Congress Control Number: 2012936069 © The Author(s) 2013 This work is subject to copyright. 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Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a speci fi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preface Building evacuations may be required in the event of a fi re, severe weather, or other emergencies. When evacuation is required, the egress system should be designed to enable the people to reach a point of safety before conditions within the building become untenable. In order to design the egress system to meet the expected objec- tives, the designer needs to be able to accurately predict the time required to evacu- ate the building. There are currently dozens of simulation models available for the designer to choose from, but the models are not well validated (Kuligowski et al. 2010). More data and a better understanding of the fundamental principles guiding egress behav- ior need to be developed (Averill 2011). This makes it even more important to know both what data has been collected to date and the different fi ndings from these studies. This book focuses on the movement of building occupants on a critical egress component – the stair. The objective is to document the fi ndings of previous litera- ture regarding movement speeds down stairs. This will be accomplished by examin- ing the assumptions, methods, and results of previous studies. The movement on stairs is critical for determining the amount of time required to safely evacuate the building. For example, the Life Safety Code (NFPA 2009) requires the maximum travel distance to an exit in a new business occupancy that is fully sprinklered to be 91 m. Assuming an approximate travel distance of 8.2 m per fl oor to a stair (Galbreath 1969), the travel distance on stairs should be greater than the maximum travel distance to reach the stair for buildings taller than 11 stories. Even for buildings less than 11 stories, occupants located closer to the stair may travel further in the stair than outside of it. Furthermore, because the stair shaft is required to be fi re-rated and means of egress cannot have occupants move to a less safe location (NFPA 2009), the stair tends to be one of the last components in many complex egress systems. Because the stairs are a major component in the egress system, an error in estimating the movement on stairs will lead to an error in the overall evacuation time. Previous fi ndings have been used to develop algebraic calculations as well as computer simulation models. The accuracy and applicability of these models are v vi Preface only valid in cases where new data is collected (or estimated) based on the same assumptions as that of the original data. This necessitates understanding what has been done in the previous studies. The fi rst section of this book describes the different types of studies that have been conducted. The second section details the measurement methods used in these studies for determining the speed and density of people on stairs. The third section then looks at the other variables that have been identi fi ed. The fi nal section dis- cusses the implication of the fi ndings. An appendix is then provided that describes the different studies in detail. References Averill JD (2011) Five grand challenges in pedestrian and evacuation dynamics. In: Peacock RD, Kuligowski ED, Averill JD (eds) Pedestrian and evacuation dynamics, 2010 Conference, Springer, New York, pp 1–11 Galbreath M (1969) Time of evacuation by stairs in high buildings. National Research Council of Canada, Fire Research Note No. 8 Kuligowski ED, Peacock RD, Hoskins BL (2010) A review of building evacuation models, 2nd edn. National Institute of Standards and Technology, NIST TN-1680 National Fire Protection Association (NFPA) (2009) Life safety code. National Fire Protection Association, Quincy Contents 1 Study Types ............................................................................................... 1 1.1 Fire Drills ........................................................................................... 1 1.2 Normal Use ........................................................................................ 1 1.3 Real Fires ........................................................................................... 2 1.4 Compiled Works ................................................................................ 2 1.5 Laboratory Studies ............................................................................. 2 References ................................................................................................... 2 2 Measurement Methods ............................................................................. 5 2.1 Movement Speed Measurements ....................................................... 5 2.1.1 Landing Calculation ............................................................... 6 2.1.2 Treads Calculation ................................................................. 6 2.1.3 Combined Travel Distance Calculation Method .................... 6 2.2 Observed Movement Speeds .............................................................. 6 2.3 Density Measurements ....................................................................... 7 2.3.1 Fluctuations in Density .......................................................... 9 2.3.2 Landing Area ......................................................................... 10 2.3.3 Tread Area .............................................................................. 10 2.3.4 Combined Landing and Tread Areas ..................................... 11 2.4 Observed Densities ............................................................................ 11 2.5 Equations ............................................................................................ 11 References ................................................................................................... 15 3 Additional Variables ................................................................................. 19 3.1 Perception of Drill .............................................................................. 19 3.2 Stair Width ......................................................................................... 20 3.3 Stair Conditions ................................................................................. 20 3.4 Exit Selection ..................................................................................... 20 3.5 Weather .............................................................................................. 21 3.6 Groups ................................................................................................ 21 3.7 Occupant Spacing .............................................................................. 21 vii viii Contents 3.8 Gender ................................................................................................ 22 3.9 Age ..................................................................................................... 23 3.10 Carrying ........................................................................................... 23 3.11 Handrail Use .................................................................................... 23 3.12 Fatigue .............................................................................................. 24 3.13 Body Size ......................................................................................... 24 3.14 Pre-evacuation Time ........................................................................ 24 3.15 Passing ............................................................................................. 25 3.16 Merging ............................................................................................ 26 3.17 Counterflow ...................................................................................... 26 References ................................................................................................... 26 4 Summary .................................................................................................... 29 References ................................................................................................... 30 Appendix A: Details of Previous Studies ........................................................ 31 List of Figures Fig. 2.1 Average speeds in references .............................................................. 9 Fig. 2.2 Reported densities in references ......................................................... 12 Fig. 2.3 Movement speed equations based on density ..................................... 15 ix