Static and Dynamic Study on the Performance of Modified Stone Column in Ahmedabad Soil

Abstract

The stone columns are frequently used as a ground improvement technique for various soils with low bearing capacities. Various researchers have performed static and dynamic analyses for the performance of stone column. The behavior of stone column can change significantly after the event of an earthquake. Very little work has been done in this area. So, it is essential to employ the study the performance of the existing stone column after the event of the earthquake. The Ahmedabad city is situated in a seismic zone III of seismic zonation map of India. Significant damages in stone columns were observed in Ahmedabad during the 2001 Bhuj earthquake. In this paper, numerical analysis of the post-earthquake behavior of stone columns installed in Ahmedabad soil has been carried out by finite element method using PLAXIS Software. The behavior of the stone columns under axial loading and the pseudo-static acceleration of 0.1, 0.15, 0.20, and 0.25 g has been studied. A study has also been undertaken to investigate the influence of different parameters like reshape of stone columns, surrounding soil of the column and the post-earthquake behavior of stone columns. According to numerical study, the bearing capacity of modified stone columns was found to be greater than that of conventional stone columns under static as well as pseudo-static acceleration. The post-earthquake behavior for all the stone columns was found to be almost similar. But modified reshaped stone column consume lesser material and hence it is more economical than the conventional column.KeywordsStone columnBearing capacityPseudo-staticPLAXIS