Abstract: Stone column is one of the most commonly used techniques for soft soil improvement in practical engineering projects. The consolidation of the soil between piles is one of the most concerned problems. Studies on the problem under different conditions have been made great progresses. In this paper, the effects of column-soil modular ratio (equivalent to steady state stone column-soil stress concentration ratio) and area replacement ratio of stone column are considered. An equal strain assumption is assumed. As well as a general time-dependent loading is transformed into Fourier series to deduce the analytical solution of consolidation. The stress applied to column and soil at any time is gained respectively. The model gives reasonable modifications to existing theories. Comparisons with other methods demonstrate that the proposed solution is reasonable and accurate. The influence of area replacement ratio and column-soil modular ratio on the soil consolidation should be considered when their values are fairly large. Furthermore, this paper also analyzes the Carrillo hypothesis that vertical and radial consolidation can be considered independently. The result shows that the hypothesis is not accurate although the general trend holds true.

Key words: stone column reinforced foundation, column-soil stress concentration ratio, time-dependent loading, consolidation, Fourier series