1. Formerly, Graduate Research Assistant, Dept. of Civil, Geological, and Mining Engineering, Ecole Polytechnique, P. O. Box 6079, Centre-Ville, Montréal PQ, Canada H3C 3A7.
2. Professor, Dept. of Civil, Geological, and Mining Engineering, Ecole Polytechnique, P.O. Box 6079, Centre-Ville, Montréal PQ, Canada H3C 3A7.
3. Professor, Dept. of Civil, Geological, and Mining Engineering, Ecole Polytechnique, P.O. Box 6079, Centre-Ville, Montreal PQ, Canada H3C 3A7.