Matthew Murphy Andrew Goulding Jennifer Young Rosanna Kleemann.
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Transcript of Matthew Murphy Andrew Goulding Jennifer Young Rosanna Kleemann.
Group 8 John Hancock TowerFacade Failure
Matthew MurphyAndrew Goulding
Jennifer YoungRosanna Kleemann
Background241m (60 storey) Skyscraper in BostonConstructed for John Hancock InsuranceTallest building in New EnglandDesigned by I.M Pei and Cobb Constructed 1968-1976 for $175MPlagued by Design and Engineering Flaws
DesignChanged Skyscraper Design
Concrete columns to concrete coresRectangular to parallelogram floor plan
Glass FacadeBlue tinted reflective glassBlends into Boston skyline
The Beginning of FailuresExcavation and foundation collapse
Swaying of the tower
Facade Failure – Falling glass
Facade FailureOne acre of glass panes failed
Falling to the streets below
Plywood panals used as temporary replacement“Plywood Palace”
Myths about FailureIncreased stesses due to swaying tower
“Hot Spots” due to rhombus shape
Increased Pressure due to Foundation Settlement
Actual Cause of FailureNew Window Design – insufficient testingBond between reflective coating and lead
spacer too strong!Bond too stiff to allow any movementIncrease stress on glass due to thermal
movement and wind vibrationsCracks formed and falling glass!
Consequences of FailureReplacement of 10,344 panes of glass by
tempered safety glass
Cost of over $8.5 Million
Delay in opening date by 4 years
ConclusionMajor Financial Implications
Delays in completion date
New Regulations on high rise building design
Improved wind tunnel testing