For a couple decades much of what I did as a metallurgical
engineering consultant involved failure analysis – figuring out why things
busted or rusted. Recently I saw that The Great Courses had a new one (released
in 2022) by Stephen Ressler titled Epic Engineering Failures and the Lessons
They Teach. I put it on hold from the Ada Community Library, and greatly
enjoyed watching all 26 lectures on 5 DVDs. Professor Ressler is a great
storyteller, and uses excellent simplified working models that show how the
structures were meant to work, and how they instead failed.
For example, on July 17, 1981 in Kansas City, collapse of
the walkways in the atrium of the Hyatt Regency Hotel killed 114 people. A
design detail change (shown above) that doubled the load applied to steel support
rods hanging the beams was not caught, due to a series of failures of both communication
and coordination.
How the process of structural design should work is shown
above via a chart (adapted from one in the course). The structural response was
tragically underestimated.
What the structural engineer had designed would have been
very difficult to build. The steel fabricator proposed a change, and spoke with
the structural engineer’s project manager. He asked them to put it in writing, but
they didn’t, and he forgot to follow up on their shop drawing. Then the steel
fabricator hired an outside engineering firm, who assumed the hanger connection
already had been analyzed, and never checked it. The fabricator sent the
completed drawings to the structural engineer. Drawings instead were reviewed
by a senior technician who hadn’t previously worked on the project. He was
unaware of the changed configuration, and didn’t raise concerns about it. It
also was missed in a design review by Kansas City Public Works.
Each of the 26 lectures could be the basis for a speech
about failure analysis. Titles for those lectures are as follows (with dates
and links to the appropriate Wikipedia pages from their List of structural failures and collapses):
1] Learning from Failure: three vignettes [Hurricane Katrina,
the Hyatt Regency Walkway Collapse, and the Dee Bridge Collapse]
2] Flawed Design Concept: the Dee Bridge [1847]
3] Wind Loading: The Tay Bridge [1879]
4] Rainwater Loading: Kemper Arena [1979]
5] Earthquake Loading: The Cypress Structure [1989]
6] Vehicle Collisions: The Sunshine Skyway Collapse [1980] and The Skagit River Bridge Collapse [2013]
7] Blast Loading: The Murrah Federal Building [1995]
8] Structural Response: The Hyatt Regency Walkways [1981]
9] Bridge Aerodynamics: Galloping Gertie [Tacoma Narrows Bridge
1940]
10] Dynamic Response: London’s Wobbly Bridge [Millennium Footbridge 2000]
11] Dynamic Response: Boston’s Plywood Palace [John Hancock Tower 1973]
12] Stone Masonry: Beauvais Cathedral [1284]
13] Experiment in Iron: The Ashtabula Bridge [1876]
14] Shear in Concrete: The FIU Pedestrian Bridge [2018]
15] House of Cards: Ronan Point [1968]
16] Brittle Fracture: The Great [Boston] Molasses Flood [1919]
17] Stress Corrosion: The Silver Bridge [1967]
18] Soil and Settlement: The Leaning Tower of Pisa [1990]
19] Water in Soil: The Teton Dam Collapse [1976]
20] Construction Engineering: Two Failed Lifts – Senior Road Tower [1982] and L’Ambiance Plaza collapse [1987]
21] Maintenance Malpractice: The Mianus River Bridge [1983]
22] Decision Making: The [Space Shuttle] Challenger Disaster[1986]
23] Nuclear Meltdown: Chernobyl [1986]
24] Blowout: Deepwater Horizon [2010]
25] Corporate Culture: The Boeing 737 MAX [2019]
26 Learning from Failure: Hurricane Katrina [2005]
My only major criticism of the course concerns Lecture 17, Stress
Corrosion: The Silver Bridge. Failure of a single eyebar, via growth of a hidden
small crack, led to a complete collapse because there was no structural
redundancy.
The Glossary in the Course Guidebook gives the following incorrect
definition for stress corrosion:
“A phenomenon in which the gradual accumulation of corrosion
product (rust) within the grain boundaries of a metal causes tiny cracks to
form. Stress corrosion occurs when the metal is subjected to tension stress in
a corrosive environment.”
For stress corrosion cracking the crack path can be either
along the grain (crystal) boundaries or across the crystals (transgranular). For
chlorides in stainless steels, it commonly is across, as discussed in the web page at Corrosion Doctors for Stress Corrosion Cracking. Also see the Corrosion
Doctors web page for the Silver Bridge Collapse, and the Wikipedia page on
Stress corrosion cracking.
Images of the Hyatt Regency Walkway collapse and connection details both came from Wikimedia Commons.
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