1. Associate Professor, School of Civil, Environmental, and Architectural Engineering, Korea Univ., Anam-Dong, Sungbuk-Gu, Seoul 136-713, South Korea (corresponding author).
2. Graduate Student, School of Civil, Environmental, and Architectural Engineering, Korea Univ., Anam-Dong, Sungbuk-Gu, Seoul 136-713, Korea.
3. Applied Construction Technology, Cleveland, OH.