Saturday, May 19, 2007

Preventing fallen arches

This poor arch at the Cathedral of St. Peter in Wilmington is not living up to its responsibilities of taking the weight above it and distributing it to its legs and down to the foundation.







It seems to be getting some help from a support right in the middle.







I remember from when I studied the ancient Romans that they got pretty good at building these arches. I imagine some engineer from Rome would be upset at needing a post in the middle.

1 comment:

Steve No_ said...

Hey! I thought you were going to tell me how to keep the connective tissue in my feet (my feets' foundments?) from going slack over age.

Keystone wear is common; one either throws shim rock in using a 100-2700lb. hammer or fills in the arch and jacks it wide to re-key it. If the engineer cannot get deterministic movement soon enough though...if the columns twist enough to make so much as anyone (hence the keeping people away whilst probing) nervous, say...and the floor mispar is sound, then rules call for this. The good news is that you can retest sometimes. They vary as to whether dressing the thing is allowed; behold, St. Mary-Kate Anorexia Nervosa, DSMV VII, Deliverer of nettle tea and leftover lo mien.