1. Professor, Faculty of Civil and Geodetic Engineering, Univ. of Ljubljana, Jamova 2, 1000 Ljubljana, Slovenia (corresponding author).
2. Research Assistant, Faculty of Civil and Geodetic Engineering, Univ. of Ljubljana, Jamova 2, 1000 Ljubljana, Slovenia.
3. Professor, Faculty of Civil and Geodetic Engineering, Univ. of Ljubljana, Jamova 2, 1000 Ljubljana, Slovenia.