Browsing by Author "Dubinchyk, Olha I."

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    Comprehensive Analysis of the Retaining Pile Structure with the Determining the Stability Factor by Numerical Methods
    (EDP Sciences, 2019) Dubinchyk, Olha I.; Petrenko, Volodymyr D.; Ihnatenko, Dmytro Yu.; Kildieiev, Vitalii R.
    EN: Abstract. The paper highlights the results of the complex analysis of the retaining pile structure with determining the stability coefficient by numerical methods. To achieve this purpose, after designing a structure with jet grouting piles, the research of the stability coefficients of the landslide hazard slopes in the software complex "OTKOS" and its stress state in the software complex LIRA-CAD system was conducted. The relevance of the completed research is to develop rational parameters of the pile structure. A comparison of determining the stability coefficient of a slope by different methods for the existing landslide stretch for the public roadways of local significance С141017 (Lviv-Shehyni) – Sudova Vyshnia was carried out. Originality of the paper lies in the fact that to determine the stability coefficient in the model, the layeredness of the slope under study is taken into account, and the nonlinear volumetric problem is solved in the course of the numerical analysis of the stress state. The rational distance between piles in the gap and the length of the pile under a certain percentage of cement and ground was justified.
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    Geotechnical Analysis of Optimal Parameters for Foundations Interacting with Loess Area
    (EDP Sciences, 2020) Dubinchyk, Olha I.; Bannikov, Dmytro O.; Kildieiev, Vitalii R.; Kharchenko, V.
    EN: The article highlights results of the geotechnical analysis of the stress and strain state for the base of a subsoil massif under its interaction with the strip foundations. The massif is represented by loess soils which while soaking give overtime subsidences that complicate the operation of a building or a structure. Through geotechnical iterative research, optimization of the parameters for strip foundations on four axes at a four-storeyed residential building is carried out. Checks are performed on two groups of limiting states for scenarios of soil occurrence in natural, moistened and compacted states. The optimum dimensions in the width of strip foundations are selected, they give approximately the same strain values of the base after the creation of the soil bedding with its layer-by-layer compaction. The relevance of this research is to develop optimal parameters in the design of strip foundations for shallow depth on subsidental loess soils.
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    Parametric Analysis of a Strain State of a Soil Base Strengthened with Vertical Elements
    (Dnipro University of Technology, 2024) Tiutkin, Oleksii L.; Radkevych, Anatolii V.; Dubinchyk, Olha I.; Kharchenko,Vitalii
    ENG: Purpose is to identify vertical displacements of the “soil base strengthened with piles or micropiles based upon drilling-mixing technology” system relying upon parametric analysis of strain state of the mentioned system, and arrangement of the strengthening elements. Methods. Mathematical modeling took place for twelve finite-element models using the computing complex SCAD intended to analyze strength of structures by means of finite-element method. Numerical analysis was carried out with variation of elastic-strain modulus of vertical reinforcing elements and change in distance between them (3d and 6d of micropiles). Findings. Results of parametric analysis have been obtained for a model without a micropile (non reinforced soil base); a model with a single micropile; a model with two micropiles where distance between them is 1.5 m, i.e. 3d of micropiles; and a model with two micropiles where distance between them is 3.0 m, i.e. 6d of micropiles. The performed comparative analysis has made it possible to obtain the results proving the hypothesis by the authors as for the specific nature of vertical displacement formation of the “soil base strengthened with piles or micropiles based upon drill-mixing technology” system. Originality. It has been identified for the first time that basing upon the standardized document for the auger or displacement piles, it is impossible to decrease efficiently vertical displacements while approaching micropiles since distance between the micropiles is 3d for elements, developed on the basis of the drilling-mixing, is minimal. Practical implications. The obtained results of a strain state may become the keystone for the development of the generalized strain theory of the composite “soil base strengthened with piles or micropiles based upon drilling-mixing technology” system as a medium differing in minor changes of strain characteristics.
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    Predicting Changes of the State of a Bridge Reinforced With Concrete Superstructures in View of Operational Changes
    (Uniwersytet Zielonogórski, Poland, 2019) Ovchynnykov, Pavlo A.; Dubinchyk, Olha I.; Tiutkin, Oleksii L.; Kildieiev, Vitalii R.; Sedin, Volodymyr; Bikus, Kateryna
    ENG: Purpose. Bridges are the most durable and heavy duty transport facilities. Therefore, the solution of scientific and technical problems of superstructure service life predicting in the context of defect and damage accumulation that is, taking into account changes in operating conditions is on the front burner. Methodology. To solve the problem of superstructure service life predicting, the work proposes the bases and methodological developments of creep theory with increasing loads as well as regression analysis of the laboratory experiments results. Findings. The main parameters of reinforcement corrosion growth in the concrete cracks were determined under laboratory experiments. Based on the obtained results the approximate analytical dependences concerning reinforcement corrosion depth change in time at a constant value of crack width were selected. The paper substantiates validity of the analytical dependences as a result of regression analysis; proposes formulas for determining the corrosion rate of rebar in reinforced concrete superstructures. The obtained analytical dependences allowed for development of the process of predicting superstructure state changes in view of operational changes. Originality. For the first time, using laboratory experiments, the development of reinforcement corrosion in concrete cracks was determined together with assessment of time-varying corrosion depth. Practical value. Approximating analytical dependences, with a high level of confidence (95%), allow predicting reasonably the crack width in reinforced concrete superstructure. This is a significant practical value for bridge superstructure service life predicting in the context of defect and damage accumulation that is, taking into account changes in operating conditions. Formulas for determining the corrosion rate in rebar with the ability to predict the active area of corroded reinforcement have also practical value.
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    Regularities of the Strain State of the Embankment when Varying the Vertical Element Length of Strengthening
    (IOP Publishing, 2024) Alkhdour, Ahmad M.; Tiutkin, Oleksii L.; Dubinchyk, Olha I.; Miroshnyk, Vitalii
    ENG: The crisis that arose during the war in the transport system of Ukraine provided an opportunity to review the concept of integrating the Ukrainian railway into the European network. Corresponding changes, which require reconstruction of the railway, including track and embankment, have been analyzed. The railway embankment needs strengthening for its normal operation. The embankment reinforced with vertical elements, namely piles, has been studied. A finite-element model of the embankment, its soil base, and the rail-sleeper grid has been created. This model shows a vertical element of strengthening with lengths of 2.0, 4.0, and 6.0 m. The results of the numerical analysis are obtained, which makes it possible to analyze the values of horizontal and vertical displacements. The values of both components of the strain state are analyzed. The results of the analysis prove that strengthening with such elements has a maximally positive effect on both components of deformation. The regularities of changes in embankment displacements, when varying the vertical element length of strengthening, are linear. They prove that the presence of piles reduces the horizontal component by 1.1 ... 1.32 times, and the vertical one by 1.1 ... 1.24 times.