1. Université Paris-Est, IFSTTAR, SPLOTT, 14-20 Boulevard Newton, Cité Descartes, 77447 Marne la Vallée, CEDEX 2, France.
2. Department of Civil and Environmental Engineering, University of Washington, 907 Saratoga Parkway, Sleepy Hollow, IL 60118.
3. Department of Civil and Environmental Engineering, University of Washington, 121E More Hall, Box 352700, Seattle, WA 98195-2700.