Behavior of Compacted Lime — (Well-graded) Soil columns: Large scale tests and numerical modelling

Abstract

This study presents the results of large scale laboratory model tests to investigate the behavior of Compacted Lime-Well-graded Soil (CL-WS) rigid stone columns in soft soils. Tests were carried out on composite specimens to evaluate the influence of different parameters such as: the diameter of the column, the slenderness ratio, area ratio and the shear strength of the surrounding soil. Finite element analysis has been also performed using PLAXIS software to compare the results of numerical and experimental modelling. In order to assess the real behavior of these columns, some tests have been carried out in the field. Based on the results, it was concluded that CL-WS columns increase the load carrying capacity of soft soils and reduce the settlement. In addition, the results show the influence of model size on the stiffness of the specimens which means that the load carrying capacity decreases by increasing the size of models. However, for specimens containing columns with diameter greater than 100 mm, the variations of stiffness become negligible and hence the results can be used to extrapolate and predict the full size behavior of these columns. A detailed comparison between the experimental and numerical modelling shows a very good agreement.