Consolidation analysis of composite foundation with multiple and reinforcements by granular columns with high replacement ratio impervious piles

The composite foundation with multiple reinforcements is a newly emerging technique to stabilize soft soils. By this technique, two or more types of differenent piles are combined to stabilize soft soils by increasing the bearing capacity, reducing the post-construction settlement and accelerating the consolidation rate. The composite foundation stabilized by the granular columns with high replacement ratio and impervious piles are selected for analysis. By considering the radial and vertical flows within the granular columns, the consolidation of the granular columns is analyzed in the same way as that for the surrounding soils. Moreover, the surcharge loads are considerd to be supported by the granular columns, the impervious piles and the soft soils together. Then the governing equation for consolidation of this type of composite foundation and the corresponding analytical solutions are derived. The rationality of the solution is futher discussed and verified. Finally, the consolidation behavior of the composite foundation is analysed.