A Literature Review of Factors Affecting the Behavior of Encased Stone Columns

Construction of structures on weak soft soils is always a great challenge to geotechnical engineers. Among various ground improvement techniques, stone columns are widely used in many soil types and foundation situations. They are inexpensive, easy to construct and environmentally satisfactory. This paper discusses the construction methods, the failure mechanism and the most important factors affecting the behavior of stone columns. It further summarizes recent published work that focus on the performance of single and grouped encased stone columns in different types of soils. A compilation of the key findings and a summary table that simplify the retrieval of data from previous experimental, numerical and field studies are also presented in this paper. The results of these studies show that encasing stone columns with geosynthetics material is a successful solution that can be used to improve the load-settlement conduct of stone column foundations. The literature review indicate a lack of studies that investigate the effect of floating encased stone columns in reducing the collapse settlement of collapsible soils. Therefore, there is a necessity to conduct a detailed study highlighting key aspects, which affect the overall performance of this technique in such soils. This might help in finding the optimum design of the floating encased stone columns and evaluate the reduction in collapse settlement.