Numerical analysis of deep vibrocompaction at small and full scale

Abstract

The numerical simulation of deep vibrocompaction, which is an efficient method for the compaction of loose granular soils, is still a challenge. In this study we make use of the Arbitrary-Lagrangian–Eulerian Method (ALE), that allows for the simulation of geotechnical boundary value problems involving large deformations. The numerical model is verified using model test results, in which the motion of the vibrator was tracked. It was thus possible to compare the vibrators’ displacement amplitude and phase angle in experiments and simulations. Experimental data from field tests are then used for the validation under a realistic stress state. It is shown that the model is able to reproduce the experimental test results remarkably well at the small as well as the full scale without any major changes. From the results it is concluded, that only a small region in the vicinity of the vibrator effectively influences the vibrator’s motion. Regarding the extent of this region, the centrifugal force is more important than the working frequency. The goal here is not to derive a practical design approach but the verification and validation of a numerical framework and model, which will help to further understand the soil mechanical processes during deep vibrocompaction.