1. Professor, Dept. of Structural and Geotechnical Engineering, Politecnico di Torino, 10129 Turin, Italy.
2. Assistant Researcher, Dept. of Structural and Geotechnical Engineering, Politecnico di Torino, 10129 Turin, Italy.
3. Assistant Professor, Dept. of Structural Engineering, Politecnico di Milano, 20133 Milan, Italy (corresponding author).