1. Dept. of Civil and Environmental Engineering and Architecture, Univ. of Parma, via Usberti 181/a, 43100 Parma, Italy.
2. Dept. of Engineering Design and Technologies, Univ. of Bergamo, V.le Marconi 5, 24044 Dalmine (BG), Italy.
3. Dept. DICATA, Univ. of Brescia, Via Branze 43, 25123 Brescia, Italy.