The experimental phase of the research described in the paper involves a centrifuge model study of consolidation and surface settlement of a storage tank located on a soft soil foundation during a filling-storage-emptying cycle. The tank is placed on a thin layer of sandfill over a weak and compressible deposit of clay soil. The clay deposit is formed by consolidating a kaolin slurry in a 40.6-cm-diameter circular mold which is subsequently moved to the centrifuge for further consolidation and “field stress” initiation. The combined processes of consolidation cause the clay deposit to form an overconsolidated layer in the upper portion and a normally consolidated layer below. This situation simulates conditions often encountered in nature. Pore water pressure transducers are embedded in the clay deposit to monitor the rise and dissipation of water pressure as a result of loading and unloading. Furthermore, the surface settlement profile of the tank bottom is measured using a number of optical-electrical displacement transducers.
The second phase of the study involved a comparison of finite-element predictions with the experimentally measured quantities. These comparisons are part of a validation study for the recently developed bounding surface plasticity model for cohesive soils. The model is calibrated using the results of standard laboratory triaxial tests for the soil in question. A system of Fortran subroutines to numerically evaluate the model has been developed and incorporated into 2-D and 3-D finite-element consolidation programs. In this study the 2-D program is used to predict the soil response for comparison with experimental results. The predicted pore water pressures and surface displacements are presented and compared with the measured values. The agreement between the pore pressure values is very good while for the displacement it is adequate.