BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
(OP)
In the Centre of FLORENCE there is an eight-curved-sided roof ontop of the cathedral. It`s not a round "arched dome" but eight curved sections meeting at a point...the top.
So each each section is bent over (in only one plane) to form the "appearance" of a dome but in reality its eight "leaning-over" walls of bricks !
For the life of me I cant figure why it doesn`t sag (horizontally) across each wall and collapse.
Any help from the experts here? Im a civil engineer so can understand a little structural stuff.
Thanks
Andy in England
[Google The Duomo Florence for an image]
So each each section is bent over (in only one plane) to form the "appearance" of a dome but in reality its eight "leaning-over" walls of bricks !
For the life of me I cant figure why it doesn`t sag (horizontally) across each wall and collapse.
Any help from the experts here? Im a civil engineer so can understand a little structural stuff.
Thanks
Andy in England
[Google The Duomo Florence for an image]





RE: BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
He is actually constructing a smaller scale of the same dome. What he discovered was that Brunelleschi (the designer/builder) used a special masonry pattern where every so often the horizontal bricks would turn vertical - sort of a herringbone pattern, that added stability to the arching masonry and prevented a full stretch of mortar joint from opening in tension.
Here are some links:
Nat Geographic Link 1
Nat Geographic Link 2
NOVA Documentary Link
You can purchase the 52 minute documentary here for US$1.99
The whole story is pretty captivating from an engineering viewpoint.
RE: BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
I did try to ask a few Florentine guides but got roundly ignored in their rudeness... tuned to a fine level ! So have been wondering about this ever since then.
It would seem to me that the brickwork ..created into almost a cast concrete slab-like material.. has an inherent strength too.
The taper of the roof is not entirely domelike either. And I suspect he "got away with it"... tapering the forces against the narrowing profile as it gets higher. A scale model would have given a great deal of feel beforehand..
I wonder how many "genius talents" like him DIDN`T get away with it and watched their structures all fall down!!
RE: BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
1. The dome isn't 8 sided - it just looks that way because of the added ribs.
2. The brickwork didn't have flat mortar joint lines - he used a "flower" pattern on the floor below and used lines to create a series of dipping joint lines - like waves - in addition to the herringbone pattern.
3. They found a buried dome nearby that was built exactly like the large dome. They speculate that this is where Brunelleschi built a mock-up to convince his masons to trust his plan.
My wife and I climbed up to the top a few years ago and it is a spectacular experience. Highly recommend it.
RE: BRICK 16century ARCHED ROOF in Florence ..I can`t figure how it works!
The other thing is I doubt very much if a DIY goldsmith would have been given the job without a least some experience and authority..even then.
I was there for a conference, so never got up the top. Next time !
Thanks for the replies. I`m not sure I can get it here in UK ... `legal reasons` come up...
Kind regards
Andy