1. Graduate Teacher, Dept. of Civil Engineering, INSA/LMDC, 135, Ave de Rangueil, 31077 Toulouse Cedex, France.
2. Research Engineer, LCPC, 58 Bld. Lefebvre, 75732 Paris, Cedex 15, France.
3. Head of Structural Laboratory, Senior Research Engineer, LCPC, 58 Bld. Lefebvre, 75732 Paris, Cedex 15, France. E-mail: t