CE 3132 – STRUCTURAL THEORY
AS/SW 01b – Case Review of a Failed Structure
Family, Given Name: Lademora, Beatrex June
Course Code/Title: CE 3132 – Structural Theory Stub Code: 1465
Date of Submission: August 8, 2023
Structure/Project Name: Hyatt Regency Hotel’s “Skywalk”
Location: Kansas City, Missouri, U.S.
Description:
The Hyatt Regency was made up of three sections: a 40story tower section, a function block, and a connecting atrium
area. The atrium was a large accessible area approximately 117
ft (36 m) by 145 ft (44 m) in plan and 50 ft (15 m) high. It was
spanned by three suspended walkways at the second, third, and
fourth floor levels. The walkways connected the tower section
and the function block. The walkway on the third floor was
independently suspended from the atrium roof trusses. On the
other hand, the second-floor walkway was suspended from the
Figure 1. Schematic diagram of
walkways
walkway located on the fourth floor, which was suspended from
the roof framing.
One year after its grand opening in July 1980, a tea
dance party was held in the hotel on July 17, 1981. About 2000
guests attended the event. At approximately 7:05 pm, two of the
suspended walkways within the atrium area collapsed killing 114
Figure 2. Walkways shortly after
collapse
individuals and injuring 200 others.
Type/s and Cause/s of Failure:
An investigation conducted by the National Bureau of
Standards (NBS), now known as National Institute of Standards
and Technology (NIST), concluded that the failure was caused
by insufficient load capacity of the box beam-hanger
connections. They also identified two factors that contributed to
the collapse.
Figure 3. Original design vs. Actual
design
The original design for the box beam-hanger connection
was inadequate. Also, the arrangement of the hanger rod was
changed during construction that led to the load of the box
beam-hanger rod connections at the fourth floor to be doubled. Initially, as approved for
construction, a set of continuous hanger rods should have been attached to the roof framing,
passing through the fourth-floor box beams and on through the second-floor box beams.
However, two sets of hanger rods were used during the actual construction. One extends from
the fourth-floor box beams to the roof framing and another from the second-floor box beams to
the fourth-floor box beams.
Overloading was also identified as a factor that contributed to the collapse. Because of
the change in the original hanger rod arrangement, the maximum load on the fourth-floor box
beam-hanger rod connections at the time of the collapse was found to be only 31 percent of the
ultimate capacity expected of a connection designed under the Kansas City Building Code. If
the original design were maintained, the ultimate capacity would have been approximately 60
percent. With the change, however, the ultimate capacity of the walkways was significantly
reduced.
It was also stated in the report that neither the quality of workmanship nor the materials
that were used to construct the walkway system was found to have a significant role in initiating
the collapse.
Analysis:
The Hyatt Regency walkway collapse was a structural failure that occurred on July 17,
1981, at the Hyatt Regency hotel in Kansas City, Missouri. The collapse killed 114 people and
injured more than 200. It was found that the project manager and chief engineer were guilty of
"a conscious indifference to their professional duties." This means that they were aware of the
risks associated with the design of the walkways, but they chose to ignore those risks. It was
also found that the engineering design for the walkways was flawed. The original design was
not safe, but the design that was used was even less safe. This was because the project
manager and chief engineer had made changes to the design without properly considering the
consequences.
This case is an important reminder of the responsibilities of engineers. Engineers have a
duty to design safe structures, and they must take all reasonable steps to ensure that their
designs are safe. They also have a duty to supervise the construction of their designs to make
sure that they are built correctly. The Hyatt Regency walkway collapse was a tragedy that could
have been prevented. Engineers must design safe structures and supervise their construction to
make sure that they are built correctly. They must also be aware of the risks associated with
their designs and take all reasonable steps to mitigate those risks.
Reflections:
As an engineering student, I was deeply troubled by the Hyatt Regency walkway
collapse. The tragedy was a reminder of the great responsibility that engineers have. We are
entrusted with the safety of the people who will use the structures that we design. One wrong
calculation or decision could have devastating consequences.
The Hyatt Regency walkway collapse was caused by a combination of factors, including
a design flaw, incorrect construction, and the failure of the structural engineer to act prudently.
This tragedy could have been prevented if the engineers had taken their responsibilities more
seriously.
I have learned a great deal from the Hyatt Regency walkway collapse. I have a deeper
understanding of the importance of accuracy and precision in engineering calculations. I also
understand the need for engineers to be extra careful when making decisions. One wrong
decision could have a ripple effect that could cost lives.
I am grateful to the engineers and other professionals who work tirelessly to ensure the
safety of our structures. They take their responsibilities seriously, and their work makes our
world a safer place.
I am also committed to become a responsible engineer. I will take my responsibilities
seriously and strive to design safe and reliable structures. I will also be mindful of the impact of
my decisions on the people who will use the structures that I design. I will take the Hyatt
Regency walkway collapse as a reminder of the importance of safety. We must never take our
responsibilities lightly as the lives of people depend on us.
Reference:
https://www.youtube.com/watch?v=jgG-gnpn0os
https://nvlpubs.nist.gov/nistpubs/Legacy/BSS/nbsbuildingscience143.pdf