1. Postgraduate Student, Dept. of Civil Engineering, Univ. of Patras, Patras GR-26500, Greece.
2. Professor, Dept. of Civil Engineering, Univ. of Patras, Patras GR-26500, Greece (corresponding author).
3. Associate Professor, Dept. of Civil Engineering, Univ. of Patras, Patras GR-26500, Greece.