1. Graduate Student Research Assistant, Lyles School of Civil Engineering, Purdue Univ., 550 Stadium Mall Dr., West Lafayette, IN 47907-2051.
2. Professor and Department Head, School of Civil and Construction Engineering, Oregon State Univ., Kearney Hall, 1491 SW Campus Way, Corvallis, OR 97331.
3. Professor, Lyles School of Civil Engineering, Division of Environmental and Ecological Engineering, Purdue Univ., 550 Stadium Mall Dr., West Lafayette, IN 47907-2051 (corresponding author).