1. Senior Geotechnical Engineer, MWH Americas Inc., 806 SW Broadway, Suite 200, Portland, OR 97205; formerly, Graduate Research Assistant, Glenn Dept. of Civil Engineering, Clemson Univ., Clemson, SC 29634-0911.
2. Professor, Glenn Dept. of Civil Engineering, Clemson Univ., Clemson, SC 29634-0911 (corresponding author).