1. Associate Professor, Dept. of Civil Engineering, Indian Institute of Science, Bangalore 560012, India (corresponding author). E-mail: venkat@civil.iisc.erent.in.
2. Research Scholar, Dept. of Civil Engineering, Indian Institute of Science, Bangalore 560012, India. E-mail: lalrichardson@hotmail.com
3. Principal Research Scientist, Dept. of Civil Engineering, Indian Institute of Science, Bangalore 560012, India. E-mail: ksn@civil.iisc.ernet.in