1. Ph.D. Student, Division of Structural and Construction Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden (corresponding author).
2. Senior Lecturer, Division of Structural and Construction Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden.
3. Ph.D. Student, Division of Structural and Construction Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden.
4. Professor, Division of Structural and Construction Engineering, Luleå Univ. of Technology, SE-971 87 Luleå, Sweden.