How deep can tunnel boring machines go?

For some reason I always wonder if earthquakes are caused by some man made activity, such as secret weapons testing. The quake in China was 6 miles down. How far  down can tunnel boring machines dig?

From Dr Bill Deagle's December 2006 Granada Forum Lecture:

I took care of John Fialla, who was best friends with Phil Schneider. How many people know about Phil Schneider? Well, they were using tunneling machines back in the mid-90s that could tunnel through a rock face at seven miles per day, that could cut through a rock face with high-energy impact lasers that could blow the nano-sized particles of rock so that there was no debris left, forming an obsidian-like core, and laying an inner core for unidirectional maglev trains that travel at Mach 2 to 2.8 underground between these very very powerful and organized cities.

There's 132 under the United States, an average of 5.36 to 7.24 cubic miles in size at an average of 1.5 to 4.5 miles underground, built, by and large, most of them in areas away from geotectonic areas - but there's going to be lots of new geotectonic faults established when you have force 11, 12, 13, 14 earthquakes hit the Earth.

Why are they rushing to do this? Because they know that catastrophe is coming. And where's this money coming from? It's not coming from our regular Black Op budget. It's coming from the illegal sale of drugs. In the United States there's at least, by conservative estimates, a quarter of a trillion to a half a trillion of illegal drugs just sold in the United States that goes directly into underground budgets, and 90-95% goes to the DUMBs [Deep Underground Military Bases].