1. Research Associate, Dept. of Civil and Environmental Engineering, Ruhr-Univ. Bochum, Universitätsstr. 150, 44780 Bochum, Germany (corresponding author).
2. Ph.D. Student, Dept. of Civil and Environmental Engineering, Ruhr-Univ. Bochum, Universitätsstr. 150, 44780 Bochum, Germany.
3. Full Professor, Dept. of Civil and Environmental Engineering, Ruhr-Univ. Bochum, Universitätsstr. 150, 44780 Bochum, Germany.