Bearing capacity improvement of medium clay soil using sodium silicate sand columns.

There is an increasing demand for multi-story buildings in Baghdad, Iraq due to the scarcity of construction space. However, most of these buildings are in the range of nine levels and are to be built on the top subsoil of a clayey layer of about 6-12 m in depth. The research aims to study the effect of end bearing and floating sand columns on medium clay and dense sandy soil as well as the mechanical strength, such as bearing capacity of the soil and settlement of the foundation. The sodium silicate end bearing and floating sand columns of different lengths to diameter (L/D) were simulated by the Mohr-Coulomb (MC) material model using a finite element method adopted by Plaxis 3D. It was shown that using sodium silicate floating sand columns on medium clay has not considerably improved the bearing capacity. However, the end bearing type can significantly enhance the bearing capacity of medium clay soil. The bearing capacity of dense sand soil decreases with an increase in L/D of more than 15. This work could be extended to analyse other soil profiles that are helpful to the future of designing foundation systems of multistory buildings on medium silty clay soil. Furthermore, future work is required to understand the deformation fields and failure mechanisms of the sand column.