What is a good source to learn geotechnical engineering principles?

Working on field.
Keen interest in observing various ongoing process.
Implementing theory into practice to resolve issues

THE TEXT WRITTEN BY BALAGURUSWAMY IS A GOOD STUDY MATERIAL,BUT IN THAT PROBLEMS ARE LESS.GEOTECHNIC DEALS WITH PROBLEMS I SUGGEST ANY OBJECTIVE TYPE BOOKS

I am strongly recommend for you : 

Foundation Analysis and Design by Joseph E. Bowles