1. Ph.D. Professor, Dept. of Engineering, Univ. of Ferrara, Via Saragat 1, 44100 Ferrara, Italy (corresponding author).
2. Associate Professor, Dept. of Civil Engineering, School of Engineering, Univ. of Minho, Azurém 4800-058, Guimarães, Portugal.
3. Full Professor, Dept. of Engineering, Univ. of Ferrara, Via Saragat 1, 44100 Ferrara, Italy.