Cracked Concrete Porch

[James H.]

The front porch / raised patio to my 1950's rental with a pier and beam foundation made of concrete and is cracked and actually depressed downward in the middle a couple inches. The floor level is about equal to that of the raised wood floor of the house. I would like to replace/repair that concrete patio floor, but am not sure how it is constructed. I'm pretty sure demo and replacement is the only way to go.

Are these things filled with dirt and then a slab poured or were they built some other way?