That caliche must be something else. I've never heard of it. But I must
question either your selection of ground rod, or method of insertion.
I've sunk a number of ground rods in semi-rock.... sometimes penetrating
granite too.

We used 5/8" copper clad steel, or sometimes 3/4" copper clad steel
rods. We also used rotary impact hammers to drive the rods down.... often
right through a rock or whatever. Worked almost all the time, and did not
"mushroom" the top of the rod.

If a 3/4" pointed solid steel rod can not be driven through Caliche with
an impact hammer I can't imagine any other tool short of dynamite doing the
job.


Ed K7AAT