They're doing soil surcharging, so that's intentional. Don't want the castle sinking into the swamp (it's on 300+ feet of silt[1]).
The steps for soil surcharging are:
1. Pile extra dirt on top of your fill.
2. Wait a sufficient amount of time (usually months/years; it's important to wait long enough[2]) as the dirt compresses and squeezes out water.
3. Remove the extra dirt (also important[2]), and build your heavy structure on top. Now the pre-loaded ground underneath won't settle, because it already did that.
Don't want the castle sinking into the swamp (it's on 300+ feet of silt[1]).
"When I first came here, this was all swamp. Everyone said I was daft to build a castle on a swamp, but I built in all the same, just to show them. It sank into the swamp. So I built a second one. And that one sank into the swamp. So I built a third. That burned down, fell over, and then sank into the swamp. But the fourth one stayed up. And that’s what you’re going to get, Son, the strongest castle in all of England."
This has been going on in South Florida for sometime. A dirt lot is filled with soil sometimes 20-30ft high. And then just as mysteriously, a few years later, it disappears.
I just assumed this was temporary storage of backfill for a construction project elsewhere.
They're doing soil surcharging, so that's intentional. Don't want the castle sinking into the swamp (it's on 300+ feet of silt[1]).
The steps for soil surcharging are:
1. Pile extra dirt on top of your fill.
2. Wait a sufficient amount of time (usually months/years; it's important to wait long enough[2]) as the dirt compresses and squeezes out water.
3. Remove the extra dirt (also important[2]), and build your heavy structure on top. Now the pre-loaded ground underneath won't settle, because it already did that.
[1] https://www.texasmonthly.com/articles/countdown-to-liftoff/
[2] http://www.straits-engineers.com/publications_pdf/publicatio...
edit: pictures of the site https://imgur.com/a/0OXkB