Tunnel modelling: stress release and constitutive aspects

Tunnel construction in soft ground has evolved significantly over the last 20 years, especially on the matter of settlement control. This was achieved by guiding theTBM operation to control the main factors that induced soil displacements, like the face pressure and the soil-lining void closure. However, the design methods and numerical modeling procedures where not adapted to these new conditions, sometimes applying boundary conditions, constitutive parameters or state variables with no physical meaning to match field measurements. This paper presents an analysis of the basic principles of plane strain numerical modeling of tunnel construction. The literature review is followed by an analysis of the stress release factor and the effects of different constitutive models to represent the soil. The tunneling convergence and settlement trough as well as the stress paths on soil elements at the crown and at springline will be presente

Deep excavations in Singapore marine clay

Geotechnical Aspects of Underground Construction in Soft Ground - Proceedings of the 5th International Conference of TC28 of the ISSMGE13-2