Dr. Nagaratnam Sivakugan is Associate Professor and Head of Civil & Environmental Engineering at the School of Engineering and Physical Sciences, James Cook University, Australia. He graduated from the University of Peradeniya, Sri Lanka with First Class Honors, and received his MSCE and Ph.D. from Purdue University. As a Chartered Professional Engineer and Registered Professional Engineer of Queensland, he does substantial consulting work for geotechnical and mining companies throughout Australia and internationally. He is a Fellow of Engineers Australia. Dr. Sivakugan has published more than 50 scientific and technical papers in refereed international journals, and 50 more in refereed international conference proceedings.Dr. Braja M. Das, Professor and Dean Emeritus, California State University, Sacramento, is presently a Geotechnical Consulting Engineer in the State of Nevada. He earned his M.S. in Civil Engineering from the University of Iowa and Ph.D. in Geotechnical Engineering from the University of Wisconsin, Madison. He is a Fellow of the American Society of Civil Engineers and is a registered professional engineer. He is the author of geotechnical engineering texts and reference books including Principles of Geotechnical Engineering, Principles of Foundation Engineering, Fundamentals of Geotechnical Engineering, and Introduction to Geotechnical Engineering. Dr. Das has served on the editorial boards of several international journals and is currently the Editor-in-Chief of the International Journal of Geotechnical Engineering. He has authored more than 250 technical papers in the area of geotechnical engineering.