1. Assistant Professor, Dept. of Civil Engineering, National Chi Nan Univ., Nantou 545, Taiwan. E-mail: wjchang@ncnu.edu.tw
2. Associate Professor, Dept. of Civil Engineering, Univ. of Texas, Austin, TX 78712.
3. Professor, Dept. of Civil Engineering, Univ. of Texas, Austin, TX 78712.
4. Senior Staff Engineer, GeoSyntec Consultants, 475 14th St., Suite 450, Oakland, CA 94612.