Thank you very much for your help! But I may not have expressed myself clearly. I have found this diagram from many books (same content, slightly different form), but I would like to know from which book exactly I uploaded this diagram, which is apparently from chapter 12 of the book. I've searched a lot of sources but couldn't find it, I'd like to know the name of the book and its author.
If you look at the references in the Drill Shaft Manual, you see this: Reese, L.C. and O’Neill, M.W. (1989). “New Design Method for Drilled Shafts from Common Soil and Rock Tests,” Foundation Engineering: Current Principles and Practices, Vol. 2, F.H. Kulhawy, Editor, ASCE, New York, pp. 1026-1039. I would start there.
