Standard Heavy Hex Nuts are one bolt diameter thick. Bolts used on many high pressure connections are considerably higher strength than the nuts. Standard tests require the bolt to fail in tension before the threads between bolt and nut strip. In applications I am familiar with the stud bolts were threaded into the body of a part one diameter deep. The body material strength was somewhere between that of the bolt and the nut used on the other end of the bolt.
The above has nothing to do with the big gouge problem. Just pointing out that there are many "rules."
Perhaps I was not complete enough in my answer. The 1.5X rule was what we used in the die business when installing a Socket Head Cap Screw (170 ksi) into a tapped hole in mild steel (60 ksi). This however is irrelevant to the discussion at hand where a 100 ksi fastener is being held in 4 ksi concrete with a 6 ksi epoxy.