Justification of Criteria and Assessment of Environmental Safety during the Operation of Metro Facilities

Introduction . In today's world, with the increasing pace of urbanization, environmental safety plays a crucial role in urban planning and management. Subway operations, as an important part of urban infrastructure, contribute to population mobility, but they can also cause significant environmental problems. Such scientists as Kulikova E.Yu., Konyukhov D.S., Potapova E.V., Balovtsev S.V., Chunyuk D.Yu., etc have studied these issues. However, their research mostly ignores the fact that one of the major threats to environmental safety is the degradation of tunnel linings due to hydrogeological processes. This not only increases the risk of accidents but also increases the likelihood of negative impacts on groundwater and the environment. Therefore, the study of the nature of the development of defects in tunnel linings and their dynamics over time is of both scientific and practical interest, and is the aim of this research. To achieve this objective, it is necessary to analyze the relationship between the condition of the tunnel lining and environmental safety based on data about defects in subway tunnel structures and their impact on the environment. Materials and Methods. For this study, we used defective sections of the subway tunnel linings from several lines of the Moscow Metro as materials. We conducted field studies of the lining's condition and geodetic surveys of the tunnels, which revealed significant changes in the indicators compared to the normative values as a result of the interaction between the human-made environment and the surrounding nature. Additionally, we employed seismoacoustic inspection methods to inspect the tunnel linings using shock excitation. Results. Data on the dependence of defect development on changes in groundwater level has been obtained. Defects in tunnel linings contribute to the leakage of chemically active substances into soil and groundwater, which threatens biodiversity and reduces water quality used by the population. Discussion and Conclusion. Field surveys have shown that defects in tunnel linings, such as cracks, concrete leaching, and waterproofing violations, have a direct impact on environmental safety. Therefore, maintaining the integrity of these structures is a key element in ensuring environmental safety in urban areas. The results of this research will form the basis for developing comprehensive proposals to improve monitoring techniques and ensure the structural integrity of tunnel structures.