Hypothetical Foundation Question
Hypothetical Foundation Question
(OP)
Let's say you have an 8 ft. tall, masonry foundation wall. If it is constructed with 6 ft. of backfill on one side and 4 ft. on the other, how is the moment determined (assuming it was backfilled simultaneously in equal lifts on each side)? Do you just assume an opposing active pressure wedge on each side or does passive resistance come into play?
Thanks
Thanks






RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
1) if you can tolerate significant movement, I believe it traditional to go active on the high side and passive on the low. Some engineers will be more conservative with the low side treatment.
2) if you want to limit movement, at rest high and low makes sense. Personally, I'll usually go at rest high and active low to be a bit more conservative.
Pin-pin Basement:
1) Same as #2 above if no SOG for some reason.
2) With SOG, active pressure and ignore everything below SOG.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
Sounds like the way to go.
Who knows? I would probably design for 3 ft. diff, specify 1 ft. and call it good.
RE: Hypothetical Foundation Question
Thanks.
RE: Hypothetical Foundation Question
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Hypothetical Foundation Question
.01h for a 96" tall wall is 1" of movement - that is a lot and rarely seen on basement walls (unless the connection slips) or retaining walls for that matter.
RE: Hypothetical Foundation Question
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Hypothetical Foundation Question
RE: Hypothetical Foundation Question
Clay has cohesion which, at least in the short term, will resist the lateral earth pressure until a certain depth (d = 2c/gamma) is exceeded. Cohesion is usually ignored in designs unless very short term. I recommend that you read any soil mechanics book. There will be discussions on active, passive, and at rest earth pressures in addition to discussion on cohesion.
www.PeirceEngineering.com
RE: Hypothetical Foundation Question
Obviously I was being facetious but the fact is that I see these vertical cuts all the time and they usually just stay like that.