[rsync]

I consult with a seismic expert at UC Berkeley about once yearly and he's pretty cavalier about pre-loading ...

Which is to say, he wants me to "pre-load the shit out of it".

Which is to say, our "indicator" is that we start to bend the HDB with the threaded rod. For instance, if we have two of these, horizontally, on either end of threaded rod:

https://www.strongtie.com/boltedholdowns_holdowns/hdb_holdow...

... he tells me to tighten that threaded rod between them until we just start to see the hold downs bend (toward each other).

So, not very scientific at all, but easy to tell that you're pre-loaded ...