New metro station “Gorny Institute” in St. Petersburg: design, construction, scientific and geotechnical support

The Saint Petersburg metro station “Mining Institute” was designed in complex mining and geological conditions, the microdistrict is characterized by dense urban development, the zone of influence during construction included buildings of historical significance and protected status, therefore, during the design, specialists from the Mining University were additionally involved for a geotechnical assessment, a number of non-standard technical and space-planning solutions were adopted aimed at reducing the negative impact on the surface. The forecast of earth's surface deformations was carried out using numerical analysis methods in a three-dimensional formulation with division into separate parts (station tunnels, main tunnels, etc.), within the framework of which the stress-strain state was modeled taking into account the adopted sequence of mining and construction works. Subsequently, the obtained values of radial and tangential contour displacements obtained on local models were transferred to a global model, including all underground structures of the station. The data of in-kind mine surveying observations of the development of subsidence of the earth's surface in the zone of influence of the station construction for the entire period of construction, objects falling into the displacement trough, and underground structures of the station excavations are analyzed. The reasons for the discrepancy between the data of in-kind mine surveying observations and the predicted values are considered. The importance of using scientifically based and practically tested criteria for assessing the degree of deformation impact is emphasized. Implementation of operational mine surveying monitoring of the condition of buildings and structures can allow timely recording of dangerous trends and implementing measures to stop deformations, preventing the development of negative consequences for the objects being undermined. The new data obtained allow further improvement of the methodology for predicting deformations of the earth's surface at similar metro construction sites in complex engineering and geological conditions.The work was carried out with the support of the Director of the Scientific Center for Geomechanics and Problems of Mining Production of the Empress Catherine II St. Petersburg Mining University, Doctor of Engineering Sciences A. N. Shabarov and the Editor-in-Chief of the journal “Gornyi Zhurnal”, Doctor of Economic Sciences A. G. Vorobiev. The authors express their gratitude to JSC Metrostroy Severnoy Stolitsy and OOO Giro for providing the field data.