Alternative ways of modelling stabilised excavations

Övrigt konferensbidrag, 2024

The realistic estimation of the soft clay response in deep excavations stabilised with lime-cement columns highly relies on the consideration of nonlinear elastoplastic soil behaviour and three-dimensional (3D) effects. In this paper, deepmix columns were simulated using both linear elastic and nonlinear elastoplastic constitutive models to illustrate their influence on the deformations of the sheet-pile wall. Model parameters were calibrated using high-quality laboratory tests conducted on both field-mix and laboratory-mix samples. Subsequently, the inherent 3D nature of stabilised soft clay was incorporated into a plane strain analysis using a volume averaging technique. The technique, implemented for 2D analysis, accommodates the use of different advanced soil models to represent the stabilised clay, consisting of the soft clay and columns.
The results indicate that relying solely on one-dimensional compression tests when modelling stabilised clay leads to an underestimation of the deformations and structural forces of the sheet-pile wall. The proposed technique maps the actual 3D problem into an equivalent 2D, thus holding the potential to efficiently capture real soil behaviour.