1. Dept. of Civil Engineering, Technical Univ. of Denmark, DK-2800 Kgs. Lyngby, Denmark (corresponding author).
2. Associate Professor, Dept. of Civil Engineering, Technical Univ. of Denmark, DK-2800 Kgs. Lyngby, Denmark.
3. Professor, Dept. of Civil Engineering, Technical Univ. of Denmark, DK-2800 Kgs. Lyngby, Denmark.