In the paper construction specificity of St. Isaak Cathedral’s underground space and engineering geological profile features are considered. The comparative assessment of condition and properties modification of water-saturated quarternary sandy and clay soils during 55 years are taken up (1954-2009). The dynamic of groundwater contamination due to leakage sewers and its aggressiveness are estimated. The researches of microbes activity in soils which are characterized by quasiheavy values are completed. The structural of complex monitoring to secure of St. Isaak Cathedral long-term stability are proposed.
This paper discusses the geobiological and hydrogeochemical processes in St.-Petersburg underground space and their role in corrosion of escalator constructional materials. The special attention were attracted to the ecological conditions which are connected with organic, inorganic contaminants and microbiota transporting to soils and groundwater from leaking sewer system and also from zones of long existing cemeteries. A detailed study and numerical analyses of escalator tunnel constructional materials were carried out to reveal biological defeat and destruction of concrete and grey iron as a result of microbiota destructive activity.