In work the influence of the buried bogs on negative transformations spreading grounds and occurrence of some exogenous processes, including biochemical phenomena. Such processes in many respects define safety of development and use of underground space of city. The special attention is inverted on marsh microflora, its number and variety of physiological groups, and also gross weight bacterial of weight. Under the certain hydrodynamical conditions marsh microbiota migrate downwards on a particles of rock. The sharp increase bacterial of weight in grounds under the buried bogs is marked in comparison with not waterlogged by sites. Is emphasized, that especially negative influence is rendered by the buried bogs on sandy adjourment, which frequently are transformed in are floating earth.
The geotechnical and geo-ecological conditions of the site of the operating building of the complex treatment of the Nevsky water BKO-1 of the South water supply station have been analyzed and assessed. Taking into account the specific geo-ecological conditions of the object under study, recommendations for the elimination of the pre-emergency condition of the above facility and the improvement of its operational reliability have been developed. Particular attention should be paid to the biochemical gas generation in the basement thickness, the high level of microbial contamination of soils, construction materials of underground structures, exterior and interior walls, as well as the load-bearing columns.
The influence of one of the important natural factors of St. Petersburg underground space (buried bogs and peat deposits) on the negative transformation of the underlying soils and the occurrence of a number of exogenous, including biochemical, processes and phenomena is considered. Such processes largely determine the safety of development and use of the underground space of the city. Particular attention is paid to the bog microflora, its number and diversity of physiological groups, as well as the total weight of the bacterial mass as a percentage. Under certain hydrodynamic conditions, bog microbiota migrate down the section on dispersed rock particles. There is a dramatic increase in bacterial mass in soils beneath buried bogs compared to unburied areas. Pollution of buried bogs by leaks from sewage systems leads to an increase in microbiological activity by 3-4 times. It is emphasized that buried bogs have a particularly negative impact on sandy sediments, which are often transformed into floats; clay soils go into quasiplastic state. Buried bogs lead to a real threat of methanogenesis, the formation of gas-mud emissions and increased gas saturation of rocks. When bog water is contaminated with sulfate, hydrogen sulfide is formed in the process of sulfate reductions. Swamp microflora forms a high degree of aggressiveness in relation to building materials.
The stadium of federal significance, Petrovsky, is located in an area whose development began in 1710, which predetermined a high degree of contamination of the cut and a significant transformation of the composition of the pound water, as well as the condition and properties of the rocks. The main source of pollution is leaks from the sewage and stormwater systems. Studies have shown that the Quaternary sediments are the most transformed, which are characterized by a high degree of microbiological contamination. In July 2000. SPGGI conducted a specialized engineering-geological survey of the Petrovsky Stadium embankment. This made it possible to identify several characteristic types of embankment destruction: the formation of failures and displacement of the lower part of the banquet, changes in the outline of the cross profile of the masonry, the fall out and displacement of the facing stones, displacement of the sidewalk slabs, failures and cracks in the asphalt pavement and the formation of landslide cirques. Embankment landslide displacements are formed under the influence of the following factors: the presence of weak lake-glacial sediments in the section, characterized by quasiplastic state and the value of coupling 0.009 MPa at zero internal friction angle, the effect of hydrodynamic pressure, groundwater and additional loads, and the gradual deterioration of sand-clay rock strength when microbiological activity is activated. The factors that determine the development of landslide processes and, accordingly, deformations of the embankment and adjacent territory, established in the process of research, show that the existing embankment design has long ago exhausted its operational capabilities and does not guarantee the stability of the slopes. In this regard, the question of complete replacement of the embankment structure with a fundamentally new one, meeting the engineering and geological conditions of the territory under consideration should be considered.
