1. Assistant Professor, Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU, College Station, TX 77843-3136 (corresponding author). E-mail: gbiscontin@tamu.edu
2. Assistant Professor, Dept. IMAGE, Univ. of Padova, via Ognissanti, 29, 35129 Padova, Italy. E-mail: simonetta.cola@unipd.it
3. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of California, Berkeley, 420 Davis Hall, Berkeley CA 94720-1710. E-mail: pestana@ce.berkeley.edu
4. Professor, Dept. IMAGE, Univ. of Padova, via Ognissanti, 29, 35129 Padova, Italy. E-mail: paolo.simonini@unipd.it