I always wondered about the Era. They drove dozens of piles into that mushy, sloppy soil. Took months.
Those piles are driven to the base of the clay layer onto bedrock.
An auger is then inserted over and over to remove the clay from the pile
A drill is then sent down and it drills into the bedrock at the same diameter as the pile.
The pile is then pushed into the bedrock as an anchor.
Water is pumped out of the Pile.
the Pile is them filled with concrete.
The building with then be anchored to the bedrock when built on top of the piles
The ERA had bedrock at 60ft then a few metres away it was 8 feet very wavy profile there.