Browsing by Author "Tkach, Taisiia"

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    The New Approach in Evaluating the Mechanism of the Blast Effect and Organizing the Blasting Operations While Tunneling
    (EDP Sciences, 2020) Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Heletiuk, Ihor; Tkach, Taisiia
    ENG: It is relevant for the organization of blasting operations with consideration to the mechanism of blast effect to justify new provisions due to the emergence of new explosives, means of initiating charges and instrumental measurement of parameters. In view of this, a new approach is needed for evaluating the mechanism of blast effect in the combined application of short-delay and delay-action blastings with a high level of organization and safety. Analyzing the results in the justification of the short-delayed blasting, obtained by many researchers in recent decades, its main advantages and some limitations in its evaluation have been identified. A clear justification for the combined application under seismic safety is provided. New results to explain the mechanism of the blast effect in the combined application of short-delay and delay-action blastings at tunneling facilities have been obtained. They help in the seismic action reduction under the conditions of close city development. Methodological approaches to organize blasting operations at complex facilities in Ukraine implemented during tunneling have been developed.
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    Regularities of the Deformed State of the Geotechnical System “Soil Base – Micropile”
    (IOP Publishing Ltd, 2022) Petrenko, Volodymyr D.; Bannikov, Dmytro O.; Kharchenko,Vitalii; Tkach, Taisiia
    ENG: Definition and predicting the deformed state of the geotechnical system "soil base – micropile" are the relevant scientific and technical objective when strengthening the soil base by reinforcing elements. The complexity of solving such a problem lies in the heterogeneity of the deformation characteristics for the parts of the specified system. The application of mathematical modeling based on the finite-element method allows defining the behavior of the deformed state in the geotechnical system "soil base – micropile" in the variation of the elastic modulus of its elements. In the course of the numerical analysis of twenty finite-element models characterized by a change in the elastic modulus of the micropile material and soil base, the value of maximum vertical displacements of the strip foundation for the civil structure is obtained. The generalization of these values makes it possible to construct diagrams of their changes in accordance with the variation of the elastic modulus. The obtained regularities allow predicting a deformed state for a sufficiently wide range of the elastic modulus for elements in the system "soil base – micropile".
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    Regularities of the Stress State of the Rock Massif Around the Single-Vault Station under Construction by NATM
    (IOP Publishing Ltd, 2022) Radkevych, Anatolii V.; Tiutkin, Oleksii L.; Kuprii, Volodymyr; Tkach, Taisiia
    ENG: Subway stations are underground facilities of high responsibility. The use of new construction technologies requires their scientific justification. The single-vault station "Teatralna" of the Dnipro Metro is designed as one that is under construction by the New Austrian tunneling method. Since this type of station is a working of a large cross-section, it is necessary to determine the stress state of the rock massif, which affects the temporary fastening. The finite-element model is developed, which shows the stages of cross-section opening. The developed model reproduces the layout of the subway station in the rock massif and the characteristics of the temporary fastening. The numerical analysis for six stages of station construction is carried out. The distributive features of horizontal stresses and the asymmetry of the stress state of the rock massif are clarified. For the first time, the regularities of the rock massif around the single-vault station under construction by the New Austrian tunneling method are obtained. It is established that the maximum of horizontal stresses appears at the stage of opening the lower left part of the cross-section.