The concrete provides a very good foundation, and dampens vibration
Foundation bolt sleeves allow elastic bolt stretch after the concrete sets, maximizing hold town force on the lathe
In addition to providing a stable, vibration absorbing base, the foundation raised the center line of the lathe to the correct working level for my height (over 6’). A very experienced turning instructor looked at me and said, “you’re going to have back problems standing (leaning) over a short lathe, you’ll need to raise it”. He said, “stand up straight, with your right arm relaxed, bend at the elbow and raise your wrist until your forearm is parallel to the ground. The distance from the ground to your elbow is about the proper center line height for your lathe”.
-- Danny, Houston, TX