Transcript Cracking of St. Peters Dome.ppt

Cracking of St. Peter’s Dome
History
St. Peters Basilica, Vatican
City
Dome designed by
Michelangelo in 1557
Died in 1624, two years
before completion
Structural problems
Cracks appear in dome during
18th century
Extent of cracking increasing
with time
Design analysis
Parabolic dome
Iron tension rings were built
into base of dome to contain
outward force
Design problems
Very large dome: dia.=42.6m
Iron tension rings were not
capable of withstanding
outward forces
Inappropriate buttressing
Remedial Actions
Structure analysed by engineer
Domenico Fontana
System of iron hoops and four
large chains added to dome to
prevent further cracking
Today
System designed by Domenico
Fontana prevented further
cracking
Outward forces have not caused
further damage to the dome
Images
Images
Any Questions?
Design analysis
Parabolic dome
Iron tension rings were built
into base of dome to contain
outward force
Design analysis
Parabolic dome
Iron tension rings were built
into base of dome to contain
outward force
Thank You
Group 21