Use at your own risk...When shotcrete is involved it is all fun and games until someone loses an eye. ;)
http://www.usace.army.mil/inet/usace-docs/eng-manuals/em.htm
There are some foundation and soils manuals that may be of some use.
Including Rock Foundations--how to anchor stuff in rock in Chapter 9 (downloadable separately). Somebody needed that the other day.
Had a lot of math in it.
http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-1-2908/toc.htm
Here is a site with tons of information - Army- Navy - other military and lots of downloadable free books.
http://www.tpub.com/