1. Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Univ. of Waterloo, Waterloo, ON, Canada N2L 3G1; Assistant Professor on leave, Dept. of Civil Engineering, Univ. of Engineering and Technology, Lahore 54890, Pakistan (corresponding author).
2. Deceased September 17, 2013; formerly, Professor and Canada Research Chair, Dept. of Civil and Environmental Engineering, Univ. of Waterloo, Waterloo, ON, Canada N2L 3G1.