Stability Analysis of retaining wall design.
Stability Analysis of retaining wall design.
(OP)
In the stability anlayis of a cantilevered retaining wall for a short roadway, with dirt on both the heel and the toe, can we use the soil above the toe in helping to provide sliding resistance?
The roadway is on the side where the toe is, and the dirt is almost up to the top of the wall on the heel side. I have heard differing opinions about this one, esp. if the footing is at least two feet below the top of paving.
One side says we cannot use it because the roadway may not be filled in when the dirt is filled on the heel side. Another side says it is ok to do so because the roadway will be in place. Thanks.
The roadway is on the side where the toe is, and the dirt is almost up to the top of the wall on the heel side. I have heard differing opinions about this one, esp. if the footing is at least two feet below the top of paving.
One side says we cannot use it because the roadway may not be filled in when the dirt is filled on the heel side. Another side says it is ok to do so because the roadway will be in place. Thanks.





RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
I doubt it would make much difference to the overturning anyway.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
On the other hand, walls should be designed such that a 250 psf surcharge is not a problem. If it is, you may be riding a little close to the edge.
Yes I realize I contridict myself. Life (and engineering) are like that sometimes.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
However, let's throw some food for thought. What is the unit weight accuracy of your backfill? Are you using actual compacted unit weights - say 135 pcf moist - or are you "assuming" a unit weight? Your assumption of 125 pcf makes a big difference if the contractor uses well graded crushed stone that could be as high as 140 pcf (10% difference in lateral pressure for a given H and ka). How much difference in lateral pressures if you determine the pressures using log-spiral or Rankine/Coulomb? My point is that there is inherent inaccuracies in any "design" of a retaining wall. How do you handle or take into account such factors . . .?
Still, AASHTO is most likely relying on long time experience of 50 state and 10 provincial departments of transportation - so I would consider using their recommendations. In other countries, I have seen 20 kPa being used.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.
RE: Stability Analysis of retaining wall design.