Analysis and design of stone columns

In this study, the behavior of stone column was investigated using full scale field test and a small scale laboratory tests. Firstly, full scale load test on a single stone column was carried out to check the performance of the executed group stone column installation on field. Long term vertical load test program was conducted to verify the consolidation process of the group stone columns. A monitoring system has been installed to measure the vertical and horizontal displacements, pore water pressure and total vertical pressure of group columns. The laboratory studies comprise an extensive series of small scale laboratory model tests. Two series of laboratory studies have been carried out. Tests with column area alone loaded were used to find the limiting axial stress and tests with entire area loaded were used to study the stiffness the modules of improved ground in unit cell for first series. Second series tests carried out in a large oedometric cell that was instrumented to measure vertical displacements with time dependent. Finally, numerical analyses were carried out with finite element based two and three dimensional software PLAXIS and the results obtained were compared with field and laboratory model tests results. Based on the results, the effects of the various parameters which govern behaviour of the stone colum are discussed and conclusions are drawn in detailed.