1. Professor, Laboratory of Civil Engineering, National Engineering School of Tunis, B.P. 32, 1002 Le Belvédère, Tunis, Tunisia (corresponding author).
2. Professor, 3SR Laboratory, UJF-Grenoble 1, Grenoble-INP, CNRS UMR 5521, Grenoble F-38041, France.
3. Graduate Professor, Laboratory of Civil Engineering, National Engineering School of Tunis, B.P. 32, 1002 Le Belvédère, Tunis, Tunisia.