jdv,
Nice dock, I like it. Lots of threads/discussions on compaction and clay, specifically in TX. I am an Ohio so can't offer a lot, they say TX dirt is an entirely different species.

Just a few:

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=395337
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=3588&page=1
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=384708

The last one, Dave Davidson1 talks about suspended sand that he had mixed in with his clay that would stay for a while after a rain. Lot more threads than these. Good luck.

Google Search: clay texas compaction site:pondboss.com