1. Assistant Professor, Dipartimento di Ingegneria Civile ed Ambientale, Università degli Studi di Perugia, Via G. Duranti 93, 06125 Perugia, Italy.
2. Research Associate, Dept. of Civil and Environmental Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
3. Senior Lecturer, Dept. of Civil and Natural Resources Engineering, Univ. of Canterbury, Private Bag 4800 Christchurch 8041, New Zealand.
4. Professor, Dipartimento di Ingegneria Civile ed Ambientale, Università degli Studi di Perugia, Via G. Duranti 93, 06125 Perugia, Italy (corresponding author).
5. Professor, Dept. of Civil and Environmental Engineering, Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
6. Associate Professor, Dipartimento di Ingegneria Civile ed Ambientale, Università degli Studi di Perugia, Via G. Duranti 93, 06125 Perugia, Italy.