Greetings Maria Fernanda,
I'm wondering about the container. You said all the parts are held together with Bonded Contact. This allows the model to solve without the soil, but is this model supposed to represent a real assembly? In a real assembly, are the parts actually glued together? If they are not actually glued together, then any side load on the wall would cause it to topple over. Look at the left wall in the image below. All the aluminum tubes and rubber spacers are the same length and are not attached in any way to the adjacent walls.
If instead the rubber spacers on the left wall were two alumimum tube width shorter, while the rubber spacers on the adjacent walls were two aluminum tubes longer, then the corner edge of the container would have rubber on the short side that reached under a long side aluminum tube. That would help keep the container together with just frictional contact. Hope that makes sense.
At some point, it might be worth replacing the solid bodies for each tube with sheet bodies of the outer faces. That will allow those faces to be meshed with shell elements which will take many fewer nodes and elements than is needed to mesh the solid body of the tubes.
If you can share your model, I can show you what I mean. Use File Archive to save a .wbpz file. Upload that file to your Google Drive (if you use Gmail) or OneDrive or other file sharing service and put the link to that file in your reply. Make sure that the link is for Anyone to download the file.