Analytical solutions for consolidation of composite ground improved by composite columns with circular and non-circular cross sections

Abstract

In recent years, a new type of composite column consisting of an impervious and stiffer core surrounded by a granular and pervious shell is emerging to improve soft soil in practice. This paper developed an analytical model for consolidation of soft ground improved by this type of composite column. Analytical solution is firstly derived for the soft soil stabilized by composite columns with circular cross section subjected to a general time-varying surcharge loading. Specially, detailed solutions are further obtained for two types of multistage loading commonly encountered in practice, i.e. a multistage instantaneously loading and a multistage ramp loading. Then, the analytical solutions are extended to the consolidation of composite column with non-circular cross section by converting it into an annulus instead of a circle. Finally, a parametric analysis and a comparison to an existing solution are performed to investigate the consolidation behavior of composite ground improved by composite columns.