I saw a TV special about this. Very interesting. It redefines gargantuan construction projects.
Settlement was an issue during construction. But they used enormous vibrating columns, pushed deep into the sand, to settle the sand.
The biggest problem seemed to be sand buildup on one side of the peninsula, caused by the prevailing current. The solution? Perpetually dredge the buildup side and deposit the sand on the other side. They have their own dedicated dredgers.
Coming next, "The World." A cluster of man made islands shaped like the world. This you have to see!
I guess there are some benefits to being insanely wealthy.