What I have to analyze is a concrete window well wall for a custom home with basement. It is unusually long - 17'-2" to be exact.
The top of wall is unsupported because of the presence of a removable steel grate.
What I normally do for short (9'-6" long) walls - and this is SWAG, to be honest - take active soil pressure (35 psf/ft of depth) x 2/3 depth of retaining (usually 7') = 245 plf of applied load (service load)
I then compute maximum "positive" bending moment based on the 9'-6" horiz. span to be wl^2/10, 245x9.5^2/10 = 2210 ft-lbs, which is OK for an 8" thick concrete wall with #5 at 12" o/c horizontal with d = 5.75".
For the 17'-2" wall, this method doesn't work - but I recall some bending moment coefficient tables for flat plates fixed on 3 edges and the 4th edge free that I used about 25 yrs ago for designing sewage treatment tanks - I can't locate these online.
I can't use any "academia" style information with calculus formulae - it has been too long since university. When I Googled for info, there were pdf's that came up with all that.
The top of wall is unsupported because of the presence of a removable steel grate.
What I normally do for short (9'-6" long) walls - and this is SWAG, to be honest - take active soil pressure (35 psf/ft of depth) x 2/3 depth of retaining (usually 7') = 245 plf of applied load (service load)
I then compute maximum "positive" bending moment based on the 9'-6" horiz. span to be wl^2/10, 245x9.5^2/10 = 2210 ft-lbs, which is OK for an 8" thick concrete wall with #5 at 12" o/c horizontal with d = 5.75".
For the 17'-2" wall, this method doesn't work - but I recall some bending moment coefficient tables for flat plates fixed on 3 edges and the 4th edge free that I used about 25 yrs ago for designing sewage treatment tanks - I can't locate these online.
I can't use any "academia" style information with calculus formulae - it has been too long since university. When I Googled for info, there were pdf's that came up with all that.
