Electrically I would suggest putting an Audio Prism Quiet Line filter on the fridge outlet. That does help keep the grunge from the fridge off the house line.
As for mechanical isolation I would suggest looking at the same things that you use in an audio system ... sorbothane pucks and such under the culprit, additional bracing in the floorboards and support struts, etc.
As for mechanical isolation I would suggest looking at the same things that you use in an audio system ... sorbothane pucks and such under the culprit, additional bracing in the floorboards and support struts, etc.