1. Lecturer, School of Engineering and Applied Science, Aston Univ., Aston Triangle, Birmingham B4 7ET, U.K. (corresponding author).
2. Executive Dean, School of Engineering and Applied Science, Aston Univ., Aston Triangle, Birmingham B4 7ET, U.K.
3. Professor, Fred J. Benson Chair, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU, CE/TTI Bldg. 503 A, College Station, TX 77843.