Measurements and Numerical modeling of stresses and deformations in the Frustum Confining Vessel for Geotechnical Model Testing

ABSTRACT: This study investigates stress distribution within a Frustum Confining Vessel (FCV), an alternative to centrifuge modeling that enables the application of realistic in-situ stress states without the need for high gravity fields. An FCV developed at Amirkabir University of Technology (FCV-AUT) was used to model stress distribution in dry sand at 40% relative density. Vertical and horizontal stresses were measured at different depths and radial distances using pressure cells. Results showed that vertical stress increases linearly with depth, while horizontal stress remains relatively uniform along the radius. Displacements of the base membrane and soil surface in the FCV apparatus were also recorded. A numerical model of the apparatus developed in Plaxis 3D showed good agreement with the experimental results. The coefficient of earth pressure at rest (K₀) varied with base pressure, particularly beyond 175 kPa. These findings support the FCV’s potential for simulating stress fields in non-axisymmetric conditions.