Parametric study of deep excavation in clays

The most challenging issue when analyzing geotechnical structures by means of finite element method is the choice of appropriate constitutive soil model, especially with reference to serviceability limit states. The paper presents parametric study of a deep excavation in clays aiming to qualify the applicability of different soil constitutive models in such specific soil conditions. Three types of constitutive models are considered in the paper: linear elastic – perfectly plastic model (Mohr-Coulomb) as a simple and well recognized reference, hypoplastic model (Hypoplastic Clay) and nonlinear elasto-plastic cap models (Hardening Soil and Hardening Soil Small). Numerical analysis was performed using two finite element codes – Plaxis and GEO5 FEM both in 2D space and the results were compared to in-situ displacements measurements. The discussion on the suitability of chosen constitutive models for advanced modelling of deep excavation in preconsolidated clays is presented.