Why is this construction site pouring gravel over a wire mesh, and then covering it with dirt?

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My office is afforded a prime view of a construction project where the workers are currently covering the leveled ground in a wire mesh, raking gravel across the entire mesh, and then covering that gravel layer in another layer of dirt.

What is the function of this, engineering-wise? I know gravel in a foundation typically is used to help with water runoff, but I can't guess why the mesh is being rolled out underneath, and this is going to become the foundation of a 3-story health pavilion, not some single-family house or storage shed (the entire footprint here with gravel and mesh will have a building on top of it, not a parking deck or a parking lot).

Is this simply a base layer of some kind, upon which concrete and rebar will be placed?

I am in the United States, in Georgia.