1. Professor, Dept. of Mining and Geological Engineering, Univ. of Alaska Fairbanks, P.O. Box 755800, Fairbanks, AK 99775-5800.
2. Graduate Student, Dept. of Civil and Environmental Engineering, Univ. of Alaska Fairbanks, P.O. Box 755900, Fairbanks, AK 99775-5900.
3. Professor, Graduate School of Engineering, Hokkaido Univ., Sapporo, Hokkaido, Japan 060-8628.
4. Professor, Institute of Low Temperature Sciences, Hokkaido Univ., Sapporo, Hokkaido, Japan 060-8628.