1. Professor and James M. Hoover Chair in Geotechnical Engineering, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 328 Town Engineering Building, Ames, IA 50011; formerly, Associate Professor, School of Civil and Environmental Engineering, Nanyang Technological Univ., Blk N1, Singapore 639798 (corresponding author).
2. Senior Geotechnical Engineer, Arup Singapore Pte Ltd., Singapore 089315.
3. Geotechnical/Structural Engineer, Falconer Bryan Pte Ltd., Singapore 079903.
4. Lecturer, Nottingham Centre for Geomechanics, Faculty of Engineering, Univ. of Nottingham, Nottingham, UK.