1. Assistant Professor, Dept. of Civil-Environmental Engineering and Architecture, Univ. of Parma, Viale Usberti 181/A, 43124 Parma, Italy.
2. Consulting Engineer, Via Zodiaco 72/1, 41126 Modena, Italy.
3. Associate Professor, Dept. of Civil-Environmental Engineering and Architecture, Univ. of Parma, Viale Usberti 181/A, 43124 Parma, Italy (corresponding author).