structural design of brick arch 1

[PSUengineer1]

thank you for reading.

Looking at 1800s brick arch opening. span is 7 feet. rise is 3.5 feet. vertical cracks at top of opening. vertical offset between brick at top of opening around 1/4 inch.

is there a design standard someone can refer me to in order to check this? This is on a small wall (about 10 feet long) on a side porch. Half the wall was falling down, has been reconstructed, and is now cracking again. trying to figure out why, maybe the span/rise ratio?

Please let me know if you have design info i can check against on historical arches. Or if you know of why this is happening please share your experience.

thanks.

 

[Celt83]

does the PSU in your username mean Penn State, If so reach out to Boothby he knows a ton about masonic arches.

Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

 

[MIStructE_IRE]

The below link gives good design guidance which I’ve used in the past. If its an old arch though there are many variables - foundation settlement, mortar decaying, brick decaying, thermal movements etc.

Is the crack uniform width? Wider at the top or bottom?

http://www.gobrick.com/docs/default...l-design-of-brick-masonry-arches.pdf?sfvrsn=0

 

[XR250]

Is there enough wall on either side of the arch to provide the necessary lateral restraint?

 

[Tomfh]

Is there enough wall on either side of the arch to provide the necessary lateral restraint?

I’m guessing not. It’s a very common failure, a masonry arch with insufficient abutment starts doing the splits...

 

[AaronMcD]

"Is there enough wall on either side of the arch to provide the necessary lateral restraint?"

Also my first thought. 7 foot span, 10 foot long wall. Better be tied into something stronger that an 18" brick wall pier.

http://www.hellodwell.design

 

[masonrygeek]

I agree with Celt83 about checking with Professor Boothby. He wrote a paper called "A Visual Classification System for Masonry Arch Failures" that shows some of the common failures of masonry arches. You can see the paper here:

http://www.hms.civil.uminho.pt/ibmac/1994/349.pdf,

but you still may want to contact Prof. Boothby since he has developed other tools to analyze arches. In most cases its all about the abutments and their movement.

 

[PSUengineer1]

thanks to all who replied. The Boothby paper is definitely worth a read.

 

[WARose]

This is one of the better pieces I've seen (from the TEK manual):

http://www.ncma-br.org/pdfs/5/TEK 14-14.pdf