Prognostic assessment of hazardous geodynamic processesimpact on underground construction in the central part of Lviv

LVIV

The purpose of this research is to conduct a predictive assessment of the impact of hazardous geodynamic processes on underground construction in the central part of Lviv. These processes are linked to specific geological structures, hydrogeological conditions, unique rock properties, and the chemical composition of groundwater. Relevance of work. In Lviv and many other large cities in Ukraine, transportation and parking problems are extremely acute. They are especially relevant for the central part of the city, which is characterised by a dense network of narrow streets, extreme vehicle saturation, dense buildings, and numerous transportation attractions.  Their design and construction require detailed information about the structure, composition, and properties of the geological environment, as well as the geological risk assessment associated with the construction and operation of such structures. Research methods.  Information on geological conditions, composition, physical, mechanical, filtration, and corrosion properties of soils, the aggressiveness of groundwater, design features of structures, types of foundations, and experience in constructing underground trams has been collected and comprehensively analysed. More than 50 experimental wells were specially drilled, and geophysical, engineering, geodetic, and laboratory studies were performed. Computer cartographic models of the geological environment were also built. Results. Based on the data obtained, the geological structure, hydrogeological conditions, physical and mechanical properties of the soils, and morphodynamic processes in the central part of the city are characterised. A spatial analysis of the risk-forming components of the geological environment is conducted, and the risks associated with its construction development are assessed. Scientific novelty. Various types of risk-forming factors for underground construction in the central part of Lviv have been identified. These factors include: geological factors that encompass structure of the rock massif, composition and condition of the rocks, their physical, mechanical and seismic properties, as well as their vulnerability to external influence; hydrogeological factors that involve the number of aquifers, depth of groundwater, their chemical composition and aggressiveness toward building structures, pressure level and the relationship between aquifers; morphodynamic factors that relate to the speed of modern tectonic movements and the development of suffosion processes and deformations of the Earth's surface. For the first time, a predictive assessment of geological risks associated with underground construction in various areas of the study region has been provided. Practical significance. The results obtained will make it possible to ensure the rational spatial location of underground parking lots and other objects of underground urbanization, to choose effective construction technologies that provide minimal risks for the stability of the designed structures and adjacent buildings and engineering infrastructure and will also serve as an information base for predicting the negative consequences of the construction and operation of underground structures in the long term.