An experimental test study on ring footing resting on clay bed reinforced by stone column

Abstract

Stone columns are used as a ground improvement technique, and they not only enhance the bearing capacity and reduce the settlement, but also serve as a primary function of reinforcement and drainage. Wrapping the stone columns with geosynthetic materials makes ordinary stone column (OSC) stronger and stiffer by enhancing its performance. Ring footings are more often provided for structures such as storage tanks and bridge piers. Stone column is generally used with square, rectangular and circular footings. The idea of using ring footing with encased stone column is very popular nowadays. By using geosynthetic-encased stone column (GESC) with combination of ring footing, more increase in bearing capacity and reduction in settlement are achieved as compared to OSC. Based on the experimental results, pressure–settlement response of the stone column-reinforced clay was studied. This paper also presents the subgrade modulus aspect of geosynthetic-encased stone column-reinforced clay bed The aim of this paper is to study the effect of different parameters such as the number of columns, length of column, diameter of column and the effect of encasement provided on OSC and GESC on bearing capacity and on subgrade modulus. The variation of bearing capacity ratio and settlement are also reported for different parameters. The experimental data were further used for regression analysis to fit the equation for bearing capacity of the improved soft clay bed. Thus, it was concluded that with the increase in the number of columns, length and diameter of column, bearing capacity and subgrade modulus of reinforced clay have increased.