1. Dept. of Civil, Environmental, Architectural Engineering and Mathematics, Università degli studi di Brescia, Via Branze 43, 25123 Brescia, Italy (corresponding author).
2. Assistant Professor, Dept. of Civil, Structural, and Environmental Engineering, Univ. at Buffalo, 224 Ketter Hall, Buffalo, NY 14260.
3. Assistant Professor, Dept. of Civil, Environmental, Architectural Engineering and Mathematics, Università degli studi di Brescia, Via Branze 43, 25123 Brescia, Italy.