1. Graduate Student, Dept. of Civil Engineering, Univ. of Toronto, Toronto ON, Canada M5S 1A4.
2. Professor, Dept. of Civil Engineering, Univ. of Toronto, Toronto ON, Canada M5S 1A4 (corresponding author). E-mail: karney@ecf.utoronto.ca
3. Associate Professor, Dept. of Civil Engineering, Univ. of Toronto, Toronto ON, Canada M5S 1A4.
4. Research Associate, Dept. of Civil Engineering, Univ. of Toronto, Toronto ON, Canada M5S 1A4.