Was just thinking of doing something similar, but the vibrations would be a pain, maybe if you could suspend (hung on wires or resting on large rubber blocks or rubber bladders like semi trucks use) a very large plate just under the floor with a pier mount in the middle, protruding through the floor. the plate would soak up most of the vibration, but would need to be (educated guess) 5-10 times heavier than the telescope. The surrounding structure would need to be very beefy. You could research shock damping in highrise buildings, this might give you some ideas. You could also build a free standing pier up through the house (gasp!) enclosed by a chase.