1. Department of Civil Engineering, ISISE, University of Minho, 4800-058 Guimarães, Portugal
2. Department of Civil and Building Engineering, and Architecture, DICEA, Univeristà Politecnica delle Marche, 60131 Ancona, Italy
3. Department of Structures and Bridges, Faculty of Civil Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia