The shape of prime base

[mmartin798]

Originally Posted by dragoon500ly

Second problem is the footprint of the excavations. Spoil. hundreds if not thousands of tons of it. Its got to go somewhere.

This is a big problem. The three rings suggested here will produce a little under 593000 cubic yards of material. This would take a Cat 797F Mining Truck about 1977 trips to haul away from the main bore hole, around 791000 tons.

If you bore near a natural cavern, you could just dump underground. Another possible solution could be to drill a network of shallow horizontal wells over a couple square miles and pump mix of water and pulverized rock into them, raising the ground level a few inches from below. Kind of like fracking, only with liquid rock into softer loam.