1. Geotechnical Research Engineer, Sato Kogyo, Morinosato Aoyama 14-10, Atsugi, Kanagawa, Japan.
2. Associate Professor, School of Civil and Construction Engineering, School of Civil and Construction Engineering, Oregon State Univ., 101 Kearney Hall, Corvallis, OR 97331.
3. Dean and Kearney Professor, College of Engineering, Oregon State Univ., 101 Covell Hall, Corvallis, OR 97331-2409.