Numerical and experimental investigation of failure of a DCM-wall considering softening behaviour

The failure behaviour of a deep cement mixing (DCM) wall due to excavation on one side of the wall was studied by means of finite element analysis and a simplified small-scale test. The DCM-wall was simulated using two constitutive models: an elastic perfectly plastic (Mohr-Coulomb) model and a concrete model, which considers tension and compression softening. Measured and simulated wall displacements were compared for different excavation stages. Structural failure of the wall with progressing excavation could be captured in the analysis using the concrete model. Furthermore, a reliable evaluation of the stress distribution and crack pattern in the wall could be obtained, which provides a step forward in the understanding of ultimate state conditions of DCM-walls. Overall the agreements between numerical simulation and laboratory experiment/field test can be considered very reasonable.