Pffft! Read a real book like "Theoretical Soil Mechanics" by Our Father Who Art in Dirt, Karl von Terzaghi, cw 1943, ISBN 0 471 85305 4. It is my "bible" and I have followed it's teachings faithfully since I saw the late night light as a young student of engineering those many years ago. What Mohr could a Christian Otto ask for than a book of mathematical relations and revelations? We all end up in the dirt. Geotechnical engineers just get dirtier than others. And they write masterpieces. Peck that apart.