1. Assistant Professor, Dept. of Civil and Environmental Engineering, Aalto Univ., Rakentajanaukio 4A, 02150 Espoo, Finland (corresponding author).
2. Independent Consultant, Otakallio 4, 02150 Espoo, Finland.
3. Associate Professor, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ., 301-A, Patton Hall, Blacksburg, VA 24061.