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Abstract: Coupled finite element analyses of the consolidation and deformation around stone columns have been performed to assess the accuracy of different analytical solutions. The numerical model reproduces the hypotheses of the closed-form solutions. In the model, a rigid load is applied to a unit cell formed by a fully penetrating column and its surrounding soil, and simple elastic or elasto-plastic soil models are used. The surface settlement, the dissipation of the pore pressure and the vertical stress concentration on the column are studied. These soil responses are accurately estimated with closed-form solutions that properly include the radial and plastic strains in the column. However, the surrounding soil does not yield for usual conditions, which reasonably justifies the elastic soil behavior assumed in the analytical solutions. The differences between drained and consolidation analyses are also evaluated. Comparing the numerical results with the closed-form solutions illustrates the implications of the assumptions of each approach. [Copyright &y& Elsevier]

Abstract: A unit cell, i.e. only one stone column and its corresponding surrounding soil, is used to study the consolidation and deformation around end-bearing columns under distributed loads. The results of laboratory measurements are compared with analytical solutions and numerical simulations. The large amount of data available from the laboratory allows for a detailed comparison. The main soil responses, such as the equivalent coefficient of consolidation, the stress concentration factor and the settlement reduction are analysed using the different approaches. The soil improvement directly depends on the stress distribution between soil and column. Column yielding, and consequently the friction and dilatancy angles of the gravel control the final improvement. Therefore, only the analytical solutions that properly consider plastic strains in the column accurately predict the soil improvement. An issue that influences the stress distribution with time and as a result the consolidation process is the high small-strain stiffness of the column, which is not considered in the analytical solutions but has a small influence for high degrees of consolidation, and hence, for practical purposes. [Copyright &y& Elsevier]