The Hyatt Regency walkway collapse

The Hyatt
Regency walkway
Dimitrellos George
Shang Lin
An introduction to a
devastating structural failure
• on17 July,1981in Kansas City,
Missouri, USA
• Two suspended walkways
collapsed during a dance
• During the collapse approximately
2000 people were in the atrium
• 114 people lost their lives
• More than 200 were injured
Background information
• Hyatt Regency Hotel was designed by the Crown
Center Redevelopment Corporation (the owner) in
• Gillum-Colaco, Inc., a Professional Engineering
Firm, G.C.E. and the architect, PBNDML
Architects, Planners, Inc. G.C.E. were hired to
provide all structural engineering services for the
implementation of the 750 room hotel project.
• In 1978 began Hyatt’s construction.
• Havens steel company signed a sub-contract in
order to fabricate and erect the atrium steel of the
Original Design
•Three suspended walkways spanned the atrium
at the second, third and fourth floor levels.
•The fourth floor walkway was suspended from the
ceiling by a set of six hanger rods.
•The second floor walkway was suspended from
the fourth floor directly underneath it by the same
set of hanger rods.
•The third floor walkway was offset from the other
two and was independently suspended from the
ceiling by another set of hanger rods.
•In the collapse the fourth and second floor
walkways fell to the atrium floor ,with the fourth
floor walkway resting on the top of the lower
•The third floor walkway remained intact.
Figure 1
The hanging suspension rods would support upper and
lower beams.
Two beams run longitudinally would bear the weight of the
In turn, both beams would rest on box beams.
The box beams consisted of two 8 inch channel sections
welded toe to toe to make up a box beam.
The ends of the box beams were drilled to receive the
Heavy washers and nuts run up to the rods to support the
box beams.
The entire length of the rods had to be threaded in order
the nut run on it.
Threading 10 m rod is difficult and expensive.
Original design
What cause the failure ?
A catastrophic modification !
•Havens Steel changed the design to simplify the assembly task and
reduce the cost.
•Engineers failed to realize that this modification was doubled the load
on the nuts under the top walkway.
•90 kN in the original design for each hanger rod.
•From the modification, each hanger rod of the top walkway had to carry
a load of 180 kN.
•The collapse began from the middle box beam of the top floor walkway.
Rod ,washer and nut hanging
from the ceiling almost intact from
the collapse.
The deformed 4th floor beam
National Bureau of Standards Investigation concluded that:
• Collapse of the walkways occurred under the action of
loads that were less than the design loads specified by
the Kansas building code.
• The capacity of the original design was sufficient to resist
the imposed loads at the time of collapse.
• The change in hanger rod from a continuous rod to
interrupted rods doubled the load to be transferred by the
fourth floor box beam.
An Engineer’s Responsibility
• to insure the safety, health, and welfare of the public
• follow all codes and standards, and uphold their
professional obligations
• Safety during the construction phase of projects
• The Kansas City Hyatt Regency Walkway Collapse
is an incident where construction safety was
compromised, leading to the eventual collapse of
the walkway.
Organizational Structure and
Who was responsible?
1. A lack of communication between the
designer and the fabricator
2. The engineering firm
3. The revised design
Responsibility of Design Engineers
• Possible reasons for design engineer’s agreeing to the
design change:
– “fast-track” nature of the project
• saving time;
• saving money;
– avoiding a call for reanalysis;
– following his immediate supervisor's orders;
– looking good professionally by simplifying the design;
– misunderstanding the consequences of his actions;
– any combination of the above
Responsibility of Fabricators and
• Design by fabricator judgment was motivated by:
– Strict adherence to the structural drawings,
– as prescribed by the AISI manual,
– under the fabricator’s discretion.
• The materials selected for the fabrication
were standard strength, size, and grade of
material, rather than what should have been
used to compensate for the added stress of
the altered design.
Responsibility of Crown
Redevelopment Corporation
• Failure to issue full on-site inspection of
hotel construction after the collapse of the
atrium roof months earlier
1. 114 people were killed and over 200 injured.
2. Many principals involved lost engineering
3. Engineers were found guilty of gross
negligence, misconduct, and unprofessional
conduct in the practice of engineering.
4. Expensive legal suits were settled out of court.
5. Several firms involved went bankrupt
From the Kansas City example, the importance of
engineer’s responsibility can be seen in aspects ranging
from design to construction.
• The collapse of the atrium roof during construction was
indicative of problems with the overall design.
• Engineers should thoroughly review all designs and
modifications made during the construction phase to
insure the safety of the project.
How Do We Prevent Similar
Events In The Future
highly complex design and construction process
Human errors
Economic pressures
It is axiomatic that someone cannot be held responsible
for achieving an objective, without commensurate
 an ineffective change management system
To prevent this type of tragedy in the future,
 A clearly defined organizational structure
 Clearly defined and enforced process procedures
 Independent constructability review
• National Bureau of Standards (May
1982). "Investigation of the Kansas City Hyatt
Regency Walkways Collapse". US Department of
Commerce. Retrieved 2011-01-26.
• ^ Baura, Gail (2006). Engineering ethics: an
industrial perspective. Academic Press.
p. 55.ISBN 978-0120885312.
• ^ a b c "Hyatt Regency Walkway Collapse". School
of Engineering, University of Alabama. Retrieved
Questions ?

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