Experimental Investigations on the Performance of Stone Columns with Different Materials for Weak Soil Improvement

Abstract

Clay soils or expansive soils are having a large void ratio and water content. The bearing capacity can be improved with the reduction of the water content and void ratio. The soil settlement could also be reduced by reducing the compressibility of the soil.  Pre compression, Vertical drains and wick drains are the prevailing methods used in practice to stabilize the soil and to improve the bearing capacity. Among the various methods for improving in-situ ground conditions, Stone columns/vertical drains are considered as one of the most versatile and economic method of ground improvement technique. Especially in weak deposits, to reduce the settlement and to increase the load carrying capacity, the installation of stone column helps to reduce the flow path length and accelerate consolidation settlement. Behavioural study has been carried out on the stone column with the materials such as stone aggregate, waste marbles, pebbles, steel slag and concrete waste are used as filler material for the erection of stone columns.  Also study has been carried out on the Unencased and encased with Geosynthetic (Geogrid) material on stone columns to stabilize the soil and to enhance the bearing capacity and drain property.  Experiments were carried out on two types of soils like Clay soil and Peat with samples collected from Coimbatore region (clay) and from Ooty hill ranges (Peat). The experimental results on the behaviour of stone columns with different materials were validated analytically using Plaxis software.