Back-analysis of K0 in overconsolidated clay on the basis of convergence measurements of a circular cavity
Abstract
In the poster, we present an investigation of the earth pressure coefficient at rest K0 by means of back-analysis of deformation measurements in underground cavity constructed in overconsolidated Brno clay. The model has been setup within Plaxis 3D software.
To represent the clay behaviour, we utilized recently developed hypoplastic model with small strain stiffness anisotropy. Soil anisotropy was shown to influence the back-analysis results significantly.
We also demonstrated, that backanalysed K0 is also influenced significantly by the neighboring exploratory gallery. The analyses indicated K0 = 0.81 in the depth of 23 m.
To verify the results, this value was subsequently used as initial condition in numerical 3D analysis of Královo Pole tunnel. The measurements of horizontal deformation by inclinometer and surface settlement trough agree well with the results obtained from the back-analysis.