International Journal of Civil Engineering Research.
ISSN 2278-3652 Volume 5, Number 3 (2014), pp. 255-260
© Research India Publications
http://www.ripublication.com/ijcer.htm
Evacuation Patterns in High-Rise Buildings
P. Sharma1, K. Dhanwantri2 and S. Mehta3
1,2,3
Amity School of Architecture and Planning, Amity University Haryana
Manesar, Gurgaon, Haryana, India.
Abstract
Buildings are built for function, beauty, fame, profit, commemoration,
fun, economy and the hierarchy of motivation depending on the owner
or developer. Safety has not been generally considered a critical factor.
But in high-rise buildings, the cost in terms of human life in a natural
disaster or man-made accident will be so high that life safety must
become the foremost consideration, starting from the concept stage.
Living and working at height are unavoidable in modern urban
environment. Countries around the world are reaching higher and
higher towards the heavens. The paper will discuss strategies
implemented for ensuring safety of occupants in tall buildings under
fire conditions. The life safety strategy must integrate key fire safety
systems with building features. The possible use of vertical
transportation for phased evacuation requires a combination of safe
havens; innovative smoke management and sophisticated
communication systems to ensure occupants under threat from fire are
moved to safe locations within the building. The height of very tall
buildings places great demand on time for occupant evacuation, fire
fighting, search and rescue and preservation of the building. In
considering fire protection measures for tall buildings, it has become
evident that the safety of occupants and fire fighting personnel depends
on the design of the building as a whole. A focus of the life safety
strategy was to protect in place. High-rise building occupants near the
fire would evacuate using the vertical transportation system; whilst
occupants remote from the fire would remain protected within the
structure. To facilitate this strategy, the fire must be kept small and the
persons in the area of fire origin must be permitted to move safely
within the structure. The key to the strategy was the design of an
integrated fire safety system, with consideration to unique building
features that influence fire and smoke spread throughout the building.
256 P. Sharma et al
Keywords: Smoke resistant lift lobbies,Intelligent Smoke Detection,
Phased Evacaution.
1. Introduction
1.1 What is 'high rise building'?
“A building whose height creates different conditions in the design, construction and
use than those that exist in common buildings of a certain region and period”.
High-rise buildings will serve better and longer if they are inspected and
maintained at regular intervals. But these activities are not often considered at the
design stage. For inspection and maintenance to be safe activities, anchors and
accessories may be designed during design and implemented during construction, more
simply and economically – and safely- than during each time the activity is to be
carried out. Buildings are built for function, beauty, fame, profit, commemoration, fun,
economy……, and the hierarchy of motivation depending on the owner or developer.
Safety has not been generally considered a critical factor. But in high-rise
buildings, the cost in terms of human life in a natural disaster or man-made accident
will be so high that life safety must become the foremost consideration, starting from
the concept stage. Living and working at height are unavoidable in modern urban
environment. Countries around the world are reaching higher and higher towards the
heavens.
In many countries, concept of safety is still not part of the professional’s
imperative. There is also the deeply ingrained feeling myth that safety concerns will
lead to greater cost and reduced productivity.
1.2 Pros and Cons of high-rise buildings
Pros:
Only solution in scarce or expensive land situations
More compact and integrated management
Easier to provide and maintain services
Symbolic of human and national aspirations
Cons
Complex and expensive to design and build
High density living makes high demands on services
Higher psychological and social stresses
More difficult to control risks and handle emergencies
Whether during or after construction, there will be occasions when:
Accidents affect workers, or,
Natural or man-made disasters affect residents.
These situations are especially critical in high-rise construction. Fires and
explosions are common examples of such emergencies.
Evacuation Patterns in High-Rise Buildings 257
Good design and construction practice require that safety controls include
appropriate rescue equipment and personnel trained in proper rescue procedures. These
may include: First aid equipment, tripods and lifting equipment to shift workers from
enclosed spaces, resuscitation equipment, fall rescue equipment, etc.
The paper will discuss strategies implemented for ensuring safety of occupants in
tall buildings under fire conditions. The life safety strategy must integrate key fire
safety systems with building features. The possible use of vertical transportation for
phased evacuation requires a combination of safe havens; innovative smoke
management and sophisticated communication systems to ensure occupants under
threat from fire are moved to safe locations within the building.
The height of very tall buildings places great demand on time for occupant
evacuation, fire fighting, search and rescue and preservation of the building. In
considering fire protection measures for tall buildings, it has become evident that the
safety of occupants and fire fighting personnel depends on the design of the building as
a whole.
A focus of the life safety strategy was to protect in place. High-rise building
occupants near the fire would evacuate using the vertical transportation system; whilst
occupants remote from the fire would remain protected within the structure. To
facilitate this strategy, the fire must be kept small and the persons in the area of fire
origin must be permitted to move safely within the structure. The key to the strategy
was the design of an integrated fire safety system, with consideration to unique
building features that influence fire and smoke spread throughout the building.
2. Fire Development & Smoke Spread
The fire scenarios used within the quantitive fire and smoke analysis for the building
were determined via a hazard analysis. Various fire scenarios were considered within
the residential, office and public areas of the buildings to determine the fire risk based
on ignition potential, frequency and consequence.
The considered “Design fires” can be categorized into three main groups
smoldering fires, flaming fires and flashover fires. Smoldering fires are generally a
poorly ventilated fire producing very little heat and thus not expected to spread beyond
the object of fire origin.
3. Egress & People Movement
As building reach for the heavens, we cannot expect building occupants to evacuate
using traditional “means of egress” via hundreds of flight of stairs. Egress down
multiple flights of stairs is expected to slow down occupant evacuation, create queuing
and bottle necks and cause injury.
4. Smoke Resistant Lift Lobbies
The provision of smoke resistant lift lobbies mitigate smoke spread via lift shafts
which connect multiple compartments. Reducing the fire and smoke hazard allows
258 P. Sharma et al
occupants on floors remote from the fire to stay in place. The lobby also provides a
safe haven for occupants and fire fighting personnel using lifts during the evacuation
of the fire floor.
The lobby needs to be of sufficient size to accommodate all people who may use
the lifts in a fire emergency with the doors closed to prevent smoke. The lobby also
needs to resist the spread of smoke and fire from the floor of lift shaft to maintain
tenable conditions for the time required for evacuation or fire fighting search and
rescue.
5. Intelligent Smoke Detection & Alarm Systems
Information is critical during a fire emergency. Data from equipments such as
detectors, remote field devices and television or security cameras in lobbies would be
valuable additional source of information to be used in a fire emergency.
6. Evacuation Procedures
High-rise buildings are required to have a Fire Safety and Evacuation Plan in
accordance with IFC 404 and approved by the Fire Department prior to final
occupancy.
Before any floor of the building can be occupied for use the following shall be
completed:
Permanent automatic sprinkler protection shall be installed on the occupied
floor and all floors below.
The permanent fire alarm system shall be installed on the occupied floor and all
floors below.
The elevator recall system shall be installed on all floors.
The emergency generator shall be in service.
The smoke control system shall be complete and functional.
An approved evacuation and life safety plan shall be in place.
7. Phased Evacuation
In phased evacuation, occupants from the zone of fire origin may be moved to another
area of the building that is protected from the fire zone. Phased evacuation is often
associated with high-rise buildings.
Phased evacuation is initiated using multiple notification devices. Horn/speakers –
voice alarms, in combination with strobe devices, are generally used to notify
occupants of a phased building evacuation. Occupants on the floor of fire origin and
the floor above and below are given a signal and message to evacuate and to re-enter
four floors below their originating floor.
The following requirements must be met for phased evacuation to be considered in
high-rise buildings:
Evacuation Patterns in High-Rise Buildings 259
1. Fire Resistive Construction: At a minimum, the building must be of fire-
resistive construction. Additionally, the building must be provided with smoke
or fire compartmentation. Most of the compartmentation is achieved through
fire-resistive building construction.
2. Full Automatic Sprinkler Protection: The building must be fully protected with
quick response automatic sprinklers. Sprinklers offer the ability to control a fire
early in its growth, while also providing an effective means of initiating the
occupant notification system.
3. Fire Alarm System: The fire alarm system must meet the requirements. Re-
entry to occupied floors from the stairwell must be unobstructed, resulting in
unlocked doors upon fire alarm signal.
4. Fire Safety management: Building management and occupant training play a
critical role in evaluating phased evacuation capabilities.
5. If phased evacuation is to be used, it is imperative that fire zone boundaries are
identical to occupant notification zone boundaries and smoke control zones. In
other words, the entire fire zone must be single zone for occupant notification
and protection, so that all occupants within the fire zone receive the same
message and level of protection.
8. Conclusions
The direction of traffic should be related to the number of persons on each floor, the
number of emergency stairwells available, and the number of floors directly exposed to
the fire or emergency. There should be a positive means of directly notifying
occupants to evacuate. Definite priority must be given to those floors directly involved
and floor immediately adjacent to the emergency. Building control will determine the
safest and most efficient means of evacuation, depending on the nature of the
emergency and scope of damage. This decision should be made known to floor control
personnel and those floors affected. Floor control personnel on the endangered floors
should be notified first.
References
[1] Chadderton, David.V., Building services Engineering
[2] K. Sushil, Standard Publishers Distributors, Building Construction
[3] www.nafoindia.org/pdfs/fire_safety_high_rise_building
[4] www.nfpa.org/safety-information/for-consumers/.../high-rise-buildings
[5] www.nyv.gov/html/dob/downloads/pdf/csw_highrise_042910
260 P. Sharma et al
