John Hancock Building
Boston, USA
Facts
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60 storeys
Beautiful blue glass Windows
Tallest building in New England
Finished in 1976
AIA National Honour Award 1977
Plagued with flaws
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Foundations
Over Budget $75M to $175 M
Sway on upper floors
Possibility of toppling
Faulty glass windows
Foundation problems
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Temporary steel retaining walls erected
to create a void on which the building
was to be built.
Walls warped and failed.
Damage to nearby buildings and utility
lines.
Faulty Glass Windows
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1.2m x 3.4m
227kg
Crashing from 240m down to sidewalk
Police closed streets during high winds
Why and How
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After much analysis, it was found that a thin
lead-tape spacer that was placed between
the double glazed windows had been the
main problem.
 This spacer was soldered to the glass which
had a reflective layer.
 The solder bonded very well with this layer
and restricted movement within the glass.
 As a result, the glazing failed.
Sway and Toppling
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Upper floor occupants suffered motion
sickness.
Solution to stabilize movement:
a tuned mass damper on the 58th floor.
Despite this damper, it was discovered
that the building still could have
toppled under certain wind loading!
1,500 tons of diagonal steel bracing
added
Problem Fixing Costs
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Between $5 million and $7 million for
glass pane replacement.
Damper, $3 million.
Added Bracing, $5 million
Numerous other costs including
foundations etc…
Lessons to be learnt
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More research required on building’s
windows and facade.
Sway and wind effects of vital
importance.
Must have an understanding of
Structural behaviour!