1. Res. Fellow, Dept. of Civ. and Envir. Engrg., Helsinki Univ. of Technol., P.O. Box 2100, FIN-02015 HUT, Finland.
2. Prof., Head of the Steel Struct. Lab., Dept. of Civ. and Envir. Engrg., Helsinki Univ. of Technol., P.O. Box 2100, FIN-02015 HUT, Finland.