When I read your question, it brings me back to several issues we faced during construction of power plants. My interpretation may be off base but I will ask you some questions:
1). What if the machine needed to be moved at some future date for whatever the reason might be?
2). Is there any reason that the machine would require a given amount of torque or tension to the foundation? If so, how would this be verified? In other words, assuming the anchor bolts were set satisfactorily, how would you ever know if somehow they loosened?
3). I guess, in my personal opinion, this sounds like a bad idea for a number of reasons, including those questions above but one more thing to consider; the anchors are likely of some hardened material, what would the metallurgical effect of welding have on the physical properties of those anchors?