1. Principal Engineer, Directorate of Civil Engineering (DCED), Pakistanian Research and Development Organization, Post Box 1138, Pak Secretariat, Islamabad, Pakistan; formerly, Research Assistant, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology (TUWien), Karlsplatz 13/202, A-1040 Vienna, Austria.
2. Associate Professor, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology (TU Wien), Karlsplatz 13/202, A-1040 Vienna, Austria.
3. Professor, Institute for Mechanics of Materials and Structures, Vienna Univ. of Technology (TU Wien), Karlsplatz 13/202, A-1040 Vienna, Austria (corresponding author).