LTNman
I think what you are looking at will eventually be a floor section of the station.
Rather than “ cut and cover “ this is more “ cover and dig”
I think you will find this section is on hydraulics allowing the underneath to be dug out, when this is done the whole section will be lowered to become the floor.
Possibly they will do this with another section using a digger and conveyor system to remove the soil.
Think we need Constuctors Input to confirm but it looks impressive.