Use of Soil–Cement Bed to Improve Bearing Capacity of Stone Columns

Abstract

Stone columns are normally used to improve the bearing capacity and reduce the compressibility of soft clayey soil. However, with the application of vertical load, stone columns bulge, and thereby possess limits to levels of possible improvement. The bulging also imposes a settlement of the overlying structure. In order to reduce the bulging and thereby to improve the load-carrying capacity, a stiff layer of soil–cement was laid over the stone columns. A series of experiments were conducted on single and groups of stone columns with and without the soil–cement bed. It was observed that with the addition of a soil–cement bed to stone columns, the lateral bulging decreases, load-carrying capacity increases, and overall settlement reduces noticeably soil–cement. This study examined the effects of the thickness of the soil–cement bed, length of the stone columns, and spacing between the stone columns on the improvement of load-carrying capacity. The results were compared with some of the previously published data on improvement of the bearing capacity of the stone columns and an encouraging result was observed.