1. Ph.D. Student, Dept. of Civil, Mining and Environmental Engineering, Div. of Structural Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden (corresponding author).
2. Professor, Dept. of Civil, Mining and Environmental Engineering, Div. of Structural Engineering, Luleå Univ. of Technology SE-971 87 Luleå, Sweden; and, Dept. of Civil Engineering, Technical Univ. of Denmark, Brovej Building 118, 2800 Kgs. Lyngby, Denmark.
3. Associate Professor, ISISE, Dept. Civil Eng., School Eng., Univ. of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
4. M.Sc. Student, ISISE, Dep. Civil Eng., School Eng., Univ. of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
5. Lecturer, Dept. of Civil, Mining and Environmental Engineering, Div. of Structural Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden.