1. Ph.D. Candidate, School of Civil and Environmental Engineering, Georgia Institute of Technology, 790 Atlantic Drive, Atlanta, GA 30332-0355 (corresponding author).
2. Professor, Geomechanics, Civil Engineering, Bauhaus-Universität Weimar, 99423 Weimar, Germany.
3. Professor, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0355.