Challenges and Improvement Solutions for Tunis’ Soft Clay

Abstract

The design of foundations resting on Tunis soft clay still remains a very challenging issue to address. However some works have been dedicated to the characterization and the study of behavior of this problematic soil on which recent investigations more focused on improvement solutions. This paper first summarizes the geotechnical properties of Tunis soft clay on the basis of data collected from experienced projects and results obtained from laboratory tests. It has been discussed how Tunis soft clay properties can be affected by disturbance? Some correlations are also suggested from recorded data. Besides, the study of behavior of built embankments on Tunis soft clay is analyzed from numerical computations carried out by 2D version of Plaxis software. It is then concluded, that the improvement of Tunis soft clay by classical techniques like geodrains, sand piles and stone columns is necessary to guarantee the short term and long term stability of structures to be built on such weak soil. Illustrated case histories show the efficiency of these improvement techniques as competitive solutions compared to piled foundation that remains the most used especially for building projects in Tunisia but not cost effective.