[1] Politecn Milan, Dept Architecture Built Environm & Construct Engn, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy
[2] Univ Nottingham, Fac Engn, Ctr Struct Engn & Informat, Univ Pk, Nottingham NG7 2RD, England
[3] Univ Minho, ISISE, Dept Civil Engn, P-4800058 Azurem, Guimaraes, Portugal