Gaps and crack...

Apparently the gaps in the XPS are because it shrinks. They went to considerable effort to put them all in the right place, and came back to find gaps had appeared, like this:






They added foam insulation on the inside,

so when they took off the frame, it looked like this:


Then later they filled in the gaps in from the outside, although some gaps still remain,


now underground.


As for the crack, apparently it's just the surface layer of the concrete, added to make an even surface to put the wooden frame on, and not structural.

.