1. Professor and Canada Research Chair in Earthquake Engineering, Dept. of Civil, Geological, and Mining Engineering, Ecole Polytechnique, P.O. Box 6079, Station Centre-Ville, Montreal, Quebec, Canada H3C 3A7. E-mail: robert.tremblay@polymtl.ca
2. Research Associate, Dept. of Civil, Geological, and Mining Engineering, Ecole Polytechnique, P.O. Box 6079, Station Centre-Ville, Montreal, Quebec, Canada H3C 3A7.