Recent advances in the design and calculation methods of stone columns. Part II: Groups of columns and secondary compression

Abstract

This paper comprises recent theoretical advances for the design and analysis of stone columns. This second part comprises some comments about the estimation of column diameter, about groups of columns and about excessive settlements induced by soil secondary compression. The number of columns, if the area replacement ratio is kept constant, has a negligible influence on the settlement reduction and the column position has a small influence on the settlement reduction. The critical column length is about twice the footing width or diameter. The paper also shows the lower effectiveness of stone columns in reducing the settlements induced by soil secondary compression. When secondary compression settlements are expected to be important, soil overconsolidation by preloading is advisable.