Rotated Segmental Retaining Wall
Rotated Segmental Retaining Wall
(OP)
Hi All,
Our company recently received a submittal for a segmental retaining wall, that will be approximately 10-12 feet in height. Typically these submittals are pretty straight forward. However, the design engineer decided to rotate the entire wall, including the foundation base, 5 degrees on top of the 5 degree rotation he had from offsetting the blocks (see attached). Also, his calculations do not reflect this rotation properly, he is still using the equations as if the wall were vertical.
Besides the fact that his calculations are incorrect, can the wall even be constructed like what he is showing? Has anyone else ever come across something like this before?
Our company recently received a submittal for a segmental retaining wall, that will be approximately 10-12 feet in height. Typically these submittals are pretty straight forward. However, the design engineer decided to rotate the entire wall, including the foundation base, 5 degrees on top of the 5 degree rotation he had from offsetting the blocks (see attached). Also, his calculations do not reflect this rotation properly, he is still using the equations as if the wall were vertical.
Besides the fact that his calculations are incorrect, can the wall even be constructed like what he is showing? Has anyone else ever come across something like this before?






RE: Rotated Segmental Retaining Wall
What's your concern? Are you used to doing straight walls with a backfill and thinking this will get a traditional backfilling?
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
No, there is no geogrid. The engineer rotated the wall this way to avoid using it.
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
One issue I have with it is that if a void ever developed behind the wall (say due to ground water, erosion, etc.), a local failure of a single block or a few blocks might result in collapse of the wall. In other words, the wall relies on the soil for stability.
In traditional wall construction, a vertical retaining wall should not fail if there is no soil behind it (i.e. a free standing wall). I assume the blocks are not connected to each other in any way.
While it may appear conservative since the wall "leans into" the soil, I don't think its a good idea for the reasons I mentioned above. There is a reason things are built a certain way.....it works.
RE: Rotated Segmental Retaining Wall
And as a side note: I think that is highly un-construct-able and the requirement for 5 degree tolerance is something only to be achieved on paper... What happens when contractor installs at 4.7 degrees? or over time it tilts away from the wall, progressive falling-over imminent?
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
@EngineeringEric, that's exactly what I was thinking when I first looked at this. I that he is relying too heavily on that rotation to counterbalance the lateral forces and like MotorCity said if a void would happen to form behind the wall that mechanism is gone.
This is actually the engineer's 3rd submittal for this wall. The first one was just horrendous, it was riddled with mistakes and errors. For the second one, he submitted his calcs with his bearing pressure way over the allowable. Now he is trying to reduce down his bearing pressure by rotating the wall.
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
Even if the Segmental Retaining Wall Design Manual is not considered an actual code, to me it is still an accepted standard of practice and should be followed.
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
RE: Rotated Segmental Retaining Wall
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