1. Dean, School of Engineering, Univ. of Virginia, Charlottesville, VA 22903 (corresponding author).
2. Assistant Professor, School of Geoscience and Environmental Engineering, Southwest Jiaotong Univ., Chengdu 611756, China.
3. Professor Emeritus, Geological Engineering, Civil and Environmental Engineering, Univ. of Wisconsin-Madison, Madison, WI 53706.
4. Gary and Rosemarie Wendt Professor, Geological Engineering, Civil and Environmental Engineering, Univ. of Wisconsin-Madison, Madison, WI 53706.