LABORATORY EXPERIMENTAL ANALYSIS ON ENCAPSULATED STONE COLUMN

摘要

The application of stone column technique for improvement of soft soils has attracted a considerable attention during the last decade. However, in a very soft soil, the stone columns undergo excessive bulging, because of very low lateral confinement pressure provided by the surrounding soil. The performance of stone column can be improved by the encapsulation of stone column by geosynthetic, which acts to provide additional confinement to columns, preventing excessive bulging and column failure. In the present study, a detailed experimental study on behavior of single column is carried out by varying parameters like diameter of the stone column, length of stone column, length of geosynthetic encapsulation and stiffness of encapsulation material. In addition, finite-element analyses have been performed to access the radial deformation of stone column. The results indicate a remarkable increase in load carrying capacity due to encapsulation. The load carrying capacity of column depends very much upon the diameter of the stone column and stiffness of encapsulation material. The results show that partial encapsulation over top half of the column and fully encapsulated floating column of half the length of clay bed thickness give lower load carrying capacity than fully encapsulated end bearing column. In addition, radial deformation of stone column decreases with increasing stiffness of encapsulation material.