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SUMMARY:Prestressing in Coventry Cathedral - Dr Chris Burgoyne
DTSTART:20150130T150000Z
DTEND:20150130T160000Z
UID:TALK57372@talks.cam.ac.uk
CONTACT:Lorna Everett
DESCRIPTION:Coventry Cathedral was completed in the early 1960s and has so
 me prestressed elements to resist lateral thrust from the roof. Other pres
 tressed structures of a similar age have had corrosion problems and this h
 as drawn attention to the fact that there is little publicly available inf
 ormation about the structural system at Coventry.  This talk addresses tha
 t issue and is in three sections.  The first summarises the four different
  prestressing systems in the cathedral and estimates the amount of prestre
 ss and its purpose in each location.  It shows that the design was based e
 ntirely on lower-bound principles using very simple analysis techniques.  
 Although there is no evidence of corrosion in the building at the moment\,
  it is impossible to inspect the existing tendons\, so the second section 
 considers what might happen to the structure if corrosion of the tendons w
 ere to occur.  It is concluded that very little warning of failure would b
 e given\, which would be especially important for the tendons over the Bap
 tistry window and those in the Nave ties.  The final section considers wha
 t could be monitored to give as much warning as possible about future prob
 lems.  \nThe effects of loss of an individual tendon\, which would not by 
 itself be sufficient to cause failure of the structure\, would cause only 
 very small strains that would be difficult to distinguish from the backgro
 und strains caused by the temperature changes.  Many of the principles dis
 cussed in the second and third sections would be applicable to most other 
 prestressed concrete structures.\n
LOCATION:Cambridge University Engineering Department\, LR5
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