Assessment of permeability and pore water pressure in Warsaw clays based on in situ measurements

Abstract

Assessment of permeability and pore water pressure in Warsaw clays based on in situ measurements. The paper presents the results of groundwater monitoring program executed for the water intake at Stegny test site and for the deep foundation of the hotel building. It has been observed that during the excavation of massive in the Warsaw clays, the hydrostatic distribution of the pore water pressure do not remain constant, but changes into a new equilibrium groundwater fl ow regime. Negative pore water pressure (due to unloading) results in the increasing of effective stress within the clay subsoil for the short time conditions. Nevertheless observations and measurements confi rmed the hydrostatic distribution of the pore water pressure for the long term conditions. This fact has to be taken into account for the estimation of the geotechnical parameters for the long term stability of the structure and the general safety.