Pressure on structure engulfed in stockpile

I posted this on the Eng-Tips website as well. Also, I’m not able to add tags.

Reversing Conveyor Structure.pdf (189.0 KB)

I’m looking for thoughts on the situation shown in the attachment. A structure supporting a reversing conveyor. The structure will become engulfed in the crushed stone stockpile. What type of lateral pressures would you use? My initial approach was:

  1. Assume only one stockpile in place.
  2. Use design material height of 56.5’
  3. Calculate pressures based on active state with an inclined backfill
  4. Apply loads to all four columns and all the beams without counting any “shielding” from the uphill columns and beams.
  5. Ignore any resisting pressure on the downhill side of the members.

I feel like this is too conservative, but I’m don’t have any sort of reference for the two things that could help.

  1. Resisting pressure on the downhill side would help. Would you use at-rest? Passive? The stockpile is gravity compacted from free-fall, so the material will just flow around the columns with no mechanical compaction.
  2. How would you handle the shielding? I think there would be some, but just assuming some percentage seems questionable.