Counterfort/buttress
Counterfort/buttress
(OP)
How do you guys justify your self when or not to use a counterfort or a buttress? Is there a deflection limit for a foundation wall?
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RE: Counterfort/buttress
RE: Counterfort/buttress
RE: Counterfort/buttress
DaveAtkins
RE: Counterfort/buttress
RE: Counterfort/buttress
RE: Counterfort/buttress
RE: Counterfort/buttress
DaveAtkins
RE: Counterfort/buttress
Buttress walls & counterfort walls beyond 6 m.
Counterfort walls have a soil load on the heel to help the FOS for overturning but the counterfort is in tension.
A buttress wall is not as efficient in overturning stability but the buttress is in compression.
I have designed several walls for dam spillways to over 10 m because a clear water way is required & buttresses would interfere with the water path.
For analysis of the face wall of either a counterfort or a buttress wall, I use 'Moments & Reactions for Rectangular Plates' by Moody - a USBR publication. Water Resources Technical Publication - Engineering Monograph 27. My copy is dated 1970 & may be out of print. It has 5 sets of boundary conditions & 11 loading cases. If a is half width & b is the depth, the range of walls is from a/b = 1/8, to a/b = 3/2. Results are moments in x & y directions & support reactions for 5 divisions in the vertical direction & 10 divisions in the horizontal direction.
BarryEng
RE: Counterfort/buttress
RE: Counterfort/buttress
Real Nice Design Info,which I found as a pdf on line.
Thanks.
RE: Counterfort/buttress
http:/
RE: Counterfort/buttress
Thank you for the info - I was not aware that it was obtainable on the net.
I was going to send a pdf copy to SlideRuleEra for his web site because I thought that it was out of print. I will now send him your info.
BarryEng
RE: Counterfort/buttress
RE: Counterfort/buttress
I used EM-27 to design some counterfort walls about 20 years. While trying to find those calculations, I came across a copy of PCA Manual ST-63 "Rectangular Concrete Tanks" (1951). The PCA example does seem a bit easier to follow than the EM-27 approach.
RE: Counterfort/buttress
RE: Counterfort/buttress
RE: Counterfort/buttress
I've just posted a msg about internal stability in retaining walls to calculate bending moments and shear in different cases (also within tieback)
I've found your post very interesting to me and I need some pdf's you were talking about (except EM-27).
I hope u'll excuse me for my bad english and my possibly misunderstanding, I'm italian-pizza-enginner
Thanks.
RE: Counterfort/buttress
RE: Counterfort/buttress
Shipping isn't so cheap; anyway last time I ordered something from outside Europe Union 3months ago), they blocked it for 2months at the dute.
I'm still browsing the web to find something but I miss the right technical words, i guess, 'cause I'm not properly an "international-engineer"... eheh.
It's obvious that i don't find anything in italian language too (books or similiare to buy).
RE: Counterfort/buttress
My post is possibly too late but I thought I would give some comments from a Colorado residential engineer in lieu of the comments from design expierience of dams and large retainging walls as posted earlier.
For all of my builders I use counterforts at a spacing of no more than 18ft (closer as the basement wall gets taller). The counterfort is typically 3ft (sometimes 4ft). I use them for ftg or piers. Becareful with piers to prevent uplift. You may need to extend the piers another 3 to 4 ft.
This is typical of most residential builders in the Denver area.
I'm curious if the PCA Rectangular Concrete Tanks gave you similar results?
RE: Counterfort/buttress
RE: Counterfort/buttress