[Vigilanteman]

I think some settling is normal for a decade or two after the artificial island is built. A good engineer plans that into the design. Over time, the settling should diminish but it will never completely go away.

Engineering and design quality plays a major role.

Why do you suppose some parts of the Appian Way, built by the Romans more than two millennia ago, are still in use but some highways built by PennDOT need to be resurfaced every other year?

[DManA]

After posting that I remembered a sci-chan show on the airport. I recall the terminal was designed with foundations that can be extended to accommodate slight subsidence and still stay level. That thing is a marvel of engineering excellence.

In defense of PennDOT, the Romans didn’t have to design for freeze/thaw cycles and salt.