1. Postdoctoral Fellow, Dept. of Civil, Architectural, Environmental, Land Planning Engineering and Mathematics, Univ. of Brescia, Via Branze 43, 25123 Brescia, Italy (corresponding author).
2. Professor, Dept. of Civil, Architectural, Environmental, Land Planning Engineering and Mathematics, Univ. of Brescia, Via Branze 43, 25123, Brescia, Italy.
3. Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto, ON, Canada M5S 1A4.