Sounds like they used post tensioned not pre tensioned.
Yep, I see a lot of post-tensioned designs in residential homes' slabs. I'm afraid that many contractors are using that design to cut back on the rebar and the concrete thickness.
> “Sounds like they used post tensioned not pre tensioned.”
I agree. I did not see any concrete “I” beams underneath the floor, which are generally pre-tensioned. It looked like they were using the entire walkway floor as the bottom flange. That means post-tensioning.
I also read that they were tightening up some cables that had loosened during the move. That means to me that they probably post-tensioned it on the side of the road and did not get the holes that the cables were in fully filled with grout. The cables broke free from the inadequate grout when it was being moved. If so, that was a construction rather than a design failure.