Geotechnical support of the zero-defect life cycle of unique sewage pumping stations in complex engineering and geological environments

Summary

For the sustainable development of megalopolises, the sustainable operation of the urban underground engineering infrastructure has been one of the prime factors where the main sewage pumping stations are unique elements. On the basis of the study of extensive pilot and experimental materials, the specific features of the operation of long-term operating head sewage pumping stations built by the method of large-sized coffers in a complex soil environment are analyzed. The results of the long-term monitoring of the technical state of structures are given, the classification of defects and the dynamics of their development are given. Based on the results of modeling the joint operation of the systems «lowerable shell of the pumping station – the inclosing geomass» and results of the experiments, the actual bearing capacity of the structure is predicted, as also preventive geotechnical measures are proposed to ensure the trouble-free life cycle of the underground structure at the pilot wastewater facilities. Geotechnological methods for protecting pumping stations with monitoring support have been developed. A unique experience of practical application of the developed methods at the stages of the life cycle of the head sewage pumping stations at the facilities of the SUE «Vodokanal of St. Petersburg», including design, construction and operation, is presented.

Key words

monitoring , complicated ground conditions , geotechnical protection measures , unique underground wastewater structures , large-sized coffer

Specific features of inspecting and innovative methods of protecting sewer tunnels in operation for a long time in unstable soils under increasing technogenic impact

Summary

An important factor in ensuring the technospheric safety associated with the increasing technogenic impact with the intensive development of megalopolises is the stability of the operation of urban underground engineering infrastructure utilities. Sewer tunnels that have been in operation for a long time in unstable soils, need special protection from man-made impacts. On the basis of the study of pilot and experimental materials, the features of the operation of deep sewer tunnels under conditions of soft soils and intense technogenic impacts are analyzed. New methods of diagnostics, defect symptoms and the results of modeling the combined action of systems «sewer tunnel – enclosing geoarray», as well as the experimental data at pilot facilities are presented. Geotechnological methods have been developed to protect long-term operating sewer tunnels. A unique experience of applying the developed methods at the facilities of St. Petersburg with monitoring support is presented. The proposed special methods for assessing the integrity health, the geomonitoring system and geotechnical methods for protecting sewer tunnel structures including the technologies for structural reinforcement and rehabilitation in conditions of wastewater transportation, provide for improving the bearing capacity of structures and their operational reliability in difficult soil conditions under increasing technogenic impact.

Keywords

monitoring , method of studying , man-induced impact , sewer tunnel structures , severe engineering-geological environment , geotechnical protection measures