brick arch easy example

huangyhg

brick arch easy example?
i have 2 (major)? arches:
span=20', rise=2', rise/span=0.1, only supports 4ft of brick veneer (0.2k/ft)
span=12', rise=3', rise/span=0.25, only supports 5ft of brick veneer (0.25k/ft)
i would like it to support itself.
does anyone have an easy formula, example, or spreadsheet?
every where i look i get complicated formulas, examples, and spreadsheets.

check out the bia at
thanks icenine! good resource.