Alternative ways of modelling stabilised excavations

Paper in proceeding, 2024

The realistic estimation of the soft clay response in deep excavations stabilised
with lime-cement columns highly relies on the consideration of nonlinear elas-
toplastic soil behaviour and three-dimensional (3D) effects. In this paper, deep-
mix columns were simulated using both linear elastic and nonlinear elasto-
plastic constitutive models to illustrate their influence on the deformations of
the sheet-pile wall. Model parameters were calibrated using high-quality labor-
atory tests conducted on both field-mix and laboratory-mix samples. Subse-
quently, the inherent 3D nature of stabilised soft clay was incorporated into a
plane strain analysis using a volume averaging technique. The technique, im-
plemented 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 effi-
ciently capture real soil behaviour.