Influence of the in situ pore water pressure on the stability of deep galleries in saturated porous media

摘要

Among the several parameters involved in the analysis of deep galleries driven in saturated porous media, the paper focuses on the pore water pressure that pre-exists in the medium. Numerical simulations clearly emphasise the influence of this factoron the magnitude of the hydro-mechanical disturbances arising in the surroundings of the gallery as well as on the short and long term soil-structure equilibrium states. Comparing those results with the existing NIM and SSP design methods developed formonophasic media, it comes out that these tools are inappropriate to calculate the stability of galleries in Saturated porous media, except for the short term equilibrium if the undrained properties of the monophasic media used in these methods were evaluated from the poro-elasto-plastic data (including the initial pore water pressure!) by means of an equivalence principle.